Here's some advice I got from Kevin (and others) over on Paintucation. There's very little in the realm of paint and body work that you can "mess up" to the point that you can't take a step back, review, redo, and correct. The key is to do your homework, take advantage of the education that's available, go slow, and realize that there aren't any shortcuts. There's a very good reason that high quality paint and body work is hideously expensive and hard to find: you're essentially paying someone else to "care" about your car as much as you do. 90% or more of a top quality paint job is in the prep and labor that happens before the first coat of color is ever applied. It's time consuming and labor intensive. It's not, however, all THAT difficult in ways similar to the ways that, say, nuclear physics or brain surgery are difficult. I spent more than a year on my 69 doing all the metal work, priming, blocking, sanding, and wet sanding on my car to get it to the point where it is now: completely wet sanded, straight, solid, no rust, and ready for sealer, color coat, and clear coat. I KNOW it's right and straight because I did every bit of the work myself and made sure. When I ran into something I didn't know how to do, I stopped until I was able to learn and practice - then I did it. When there was a tiny defect in a panel, a high spot or a low spot, I kept working on it and re-applying surfacer (or glaze or filler, or redoing the metal work), block-sanding, re guide-coating, re-sanding, until it was dead nuts straight. It probably took me more "iterations" to get it right than it would have a pro, but the point is - I was able to eventually get it right. I know where every square inch of patched metal is on this car, I know exactly how every weld was done, and I know for an absolute fact that there's no filler on it -anywhere- that's thicker than a sixteenth of an inch. I know what kind of prep was done to all the areas that aren't visible, the braces behind the front fenders where I had to patch some rust, and the same on the hood braces. When I finally start spraying sealer, color, and clear I'll know for certain exactly how much time each coat was allowed to flash, what the air and metal temps were when it was sprayed, how many coats of each (and what brands) are on there, how each layer was mixed and strained, and also that no recoat time "windows" were missed. Unless you're standing over the guy when someone else does the work, those are all things that you just have to take on faith that they'll do correctly because none of it will "show" - at least not until well after you've paid the bill.
There's a cost in terms of time - I had no idea how much work was involved, I've sanded every square inch of this car, by hand, probably at least a dozen times. I wasted a lot of material (primer, surfacer, filler) learning how to work with it and how to get it right. I learned (painfully) not to trifle with trunk lid springs, and I learned (eventually) to remember to put on a mask before grabbing a sanding block (cough cough). Unless I chicken out now, I'm going all the way to the end myself and will do the sealer, color, clear, color-sanding, and buffing. I "hope" to have it done by the time summer arrives, but then I've never been very good at estimating the time required.
The point is, this is the very first time I've done any of this. I started just like you, knowing very little about any of it. I got lucky in finding both the Paintucation DVD's and forum - everything I've accomplished so far, I learned from there and from talking to the people I got my materials from. Southern Polyurethanes, especially, was very helpful.
Trust me when I say, if I can do it - probably anyone can. Just go slow, double check everything, and if something goes wrong - stop, until you're confident you know how to make it right.