Long and wordy post warning!
First off, find out what you normally spend to live on. http://www.rvjunkie.com/otherstuff.html
has a budget spreadsheet (Excel) that I used as a basis for my Open Office budget spread sheet (mine resembles the original very little, mostly because I set up Monthly sheets with daily entries that automatically fill in to the front budget sheet). Don't worry about filling in the "budget" part, just keep track of your monthly expenses and income. You have to know that before you can set up a budget. Chances are your spending won't change with your lifestyle. To be a full-timer, you simply cannot survive this lifestyle if you have debt. It will eat you alive. So work on getting everything paid off. BTW, our site rental in private and public parks have been running under $400 per month and that normally includes all utilities. We DO NOT stay in "resort" type places. Part of the reason it is so low is because we pay the "monthly" rates. Usually the monthly rate is roughly equal to about 2 to 3 weeks nightly site rental. needless to say, most full-times will stay longer in one spot to take advantage of the monthly rates. And you will need a mail forwarding service unless your family's more dependable than mine is about the mail. Escapees is one of the best but you have to join Escapees to use it. Also you will need a "domicile" to make the government happy. As fulltimers with no home base to speak of, we will end up transferring all our stuff from TN (who has gotten to be a little difficult to deal with) to TX using the Escapees Mail Forwarding as a "home address". SD is also an alternative. Where ever you choose, remember, you will need to go to that state every so often to renew your drivers license. I have been renewing my TN license on line until the last year when they informed me that I had to show up for a picture. I am currently in NM. So I now have an expired license. Just gotta get a NM one. Requires some paperwork that I do not have. We renew tags online as well. It's amazing what you can do online.
You can't have a lot of "stuff" so sell off what you can't live without (it's liberating and painful). Books and tools are a problem for me. Once the bus is converted, the last of the woodworking tools will be sold at a yard sale (at "get rid of it" prices).The only tools we will keep is the ones we will really need. And part of them will be replaced with smaller battery operated versions. My books... Except for my small collection of leather bound books, I am shifting my book collection to electronic form. I will need to get a laptop (Can't have those "dedicated to a single purpose" nooks/kindles) as the e-book reader programs can be downloaded for free off the internet and many magazines are now in electronic form as well.
You need a source of income, unless you are independently wealthy. While the idea of having a "business on the road" is grand, it's also full of problems depending on the type of business. If you are going to have an internet based business, get it up and running now so you aren't working the bugs out of it while traveling. Also that way you will have an idea of the $$ it is bringing in. With a good WI-FI antenna, we hit free Wi-Fi hotspots in every parking lot we stayed in on our way out west. Currently we have free Wi-Fi in the park... you will want an antenna in some parks as well. Some park Wi-Fi sucks, even the ones you pay for like TENGO. I use http://www.wefi.com/
to find various Wi-Fi sites. You can work for a "chain" of stores. Many big box and smaller retail stores like having folks in their "system" that can travel to other stores(I've heard Wal-Mart loves their mobile seasonal workers). And then there is also Amazon who LOVES their RV workers. It will tie you to one place anywhere from a couple of months to a year or more. One of my daughters started out working for Family Dollar last summer. It's been almost a year and they are training her now to be management (she's only 24 yo). The plan is for her to work here for another year or two to get enough management training and then she will transfer back east somewhere. If she had just wanted to stay as a cashier, she could still transfer to various stores within the Family Dollar system. Ultimately, she wants to get Family Dollar to set her up as a "floating" manager for newly opened stores to train their management and staff and to be shifted into "troubled" stores to retrain the help. Basically, cashiers, waitstaff, short order cooks, hotel staff (front desk) can all walk into jobs in any decent sized town. Just be able to pass the increasingly required drug test and show up for work. BTW, you will pay taxes on $$ you earn in each state. As a TN resident, I have/had no state income tax (neither does TX). For 2009, I paid fed taxes plus NC state income taxes as a non-resident because I worked in NC (front desk) and David had the food cart so we also paid income taxes PLUS filed sales taxes monthly on everything sold in the state. For 2010,I paid FED/NM State income taxes on income we earned in NM PLUS the monthly sales taxes PLUS I paid Fed taxes on the income we earned in TX (no state income taxes there) PLUS the monthly sales taxes to TX for what we sold. I file all my taxes online. I used NM state site for their taxes, TX state website to file monthly sales tax and I used Turbo tax (?) to file Federal taxes. I don't think I paid to file any taxes but I may be wrong. Since we have dumped our checking accounts (it's an experiment that seems to be working well for us), I had the refund checks sent to my other daughter's mailing address and picked up our refund check a week later (she's lousy at mail forwarding) and put the entire thing on a Wal-Mart Visa Debit Money Card that I got for free (saved $3) off the internet. Cost $3 to reload the card and I can hold up to $3K on the card (same protections as a regular Visa credit card). My bank (BOA) was charging me $12 per month for basic bank fee. I also have a PayPal Debit Mastercard (again, same protections as a regular Mastercard credit card) to access my PayPal $$ in my PayPal (business) account. My Money card is listed on my PayPal account as the back up credit card. I haven't written a check in over a year. We have decided to pay cash for everything and use the tow card for the few times we need plastic (like internet purchases and unmanned fuel pumps). Also I have a Sam's Club gift card that I can load up to $500 on to pay for fuel at their pumps (they don't take cash at their pumps). The Sam's Club card is also able to be used at Wal-Mart and I think (but not sure) that I can use the gift card at the Murphy fuel pumps. We have a business membership at Sam's... $35 per year which is cheaper than regular membership and you don't have to prove you are a business. Plus we get in early. They put out fresh coffee and danishes/cookies for the special early hours for business members... works great for when we park in their parking lot over night. Not worth having the membership just for fuel since not all Sam's have diesel pumps.
As for the bus, you may or may not be able to buy an already converted bus as cheap or cheaper than you can do it yourself. The plan for our daughter (the one who works for Family Dollar) is to have her live in our Class C for a year or so and see what requirements she decides she needs and wants (in that order). Then we will watch for an already converted bus that will come very close to matching her needs/wants. This way we will have to only do a little remodeling, not a major rebuild. We simply can't do a major rebuild in a campground, but we can probably do a minimal remodel. I know we can paint/stain interiors while in a campground because I've done it on the Class C (Georgia Veterans State Park). I also painted/repaired parts of the Class C's exterior while in GA as well (Dixie RV Park on the back side of Vienna GA... only ones in the whole campground). We can park in the "boonies" to build laminate on plywood countertops, install flooring, even paint the exterior. All minor work for us.
BTW, getting WVO while on the road will be a PITA. If you do go the WVO, make sure you can use that as an option not as the only fuel.