None of it is that difficult, really. Yes, web applications are hard; web sites are merely scary 'cuz its all like computery and stuff and you've never done it before. So the first thing to do is relax a bit, understand that you will be able to do it (and may make a few unimportant and correctable mistakes while getting used to doing it) and think more about what you want to do.
"A web site about airbrushing" isn't a starting point, either for you or for us. That can mean just about anything. Off the top of my head, I can think of:
1) something that's essentially an online book, starting with selecting a brush (external vs internal mix, single versus double action, a quick peek at the Paasche Turbo to scare off people who aren't really serious, air source (canned air, large air tank you take to the gas station to refill, diaphragm and piston compressors, bottled CO2/nitrogen) and media (watercolors, dyes, acrylics, laquers, etc.), then moving through freehand, hard (frisket) and soft masking... You know -- just like a "dead tree" book, but online.
2) a tutorial site that assumes some knowledge of the basics and offers tips and tricks on creating certain effects (likes Mike Lavallee's or Chuck Bauman's flames, a quick way to do leather textures, getting believable chrome, that sort of thing).
3) a gallery of your work, either just to show off or as an advertisement for commisions.
4) a review site talking about brushes, paints, compressors, tapes, friskets, commercial masking templates/kits and instructional books/videos.
5) a painter-to-painter forum for swapping techniques and equipment/paint/masking material recommendations.
You may want to combine more than one of those options into your "site about airbrushing", but you have to have some idea of what you want to do before you can start creating it. Most of it can be done with some combination of a blog (like WordPress) a forum (I can't recommend a simple one; I usually use my own software for discussions) and YouTube.
Give it some thought, tell us what you want to do, and we can be of a lot more help.
