Kevin- congrats on getting into tying.
The woolly bugger is a great pattern for beginners-- the size large enough to be manageable, the materials are relatively inexpensive and can be used for a lot of other patterns they teach a lot of different tying techniques you'll use on other patterns-- and, as a bonus, they can be really effective patterns and it's hard to fish them wrong.
Woolly Buggers can be tied from size 2 to 12, but a size 8 woolly bugger tied on a 3 extra long hook would be a good all around choice for all 3 types of fish (trout, small bass, and the occasional panfish), with a size 6 being more of a meal for trout and bass but probably too big for panfish. Add some lead or non toxic "lead" wire wraps or a bead head for additional weight.
As Lancer said buggers don't look very much like anything in particular, but they do sort of vaguely resemble a wide variety of different types of food, and the way the marabou tail and hackle pulse in the water on the retrieve sends out a lot of eat me signals. Black ones can look like leeches in ponds and lakes, large stonefly nymphs in streams, and baitfish. Olive ones resemble damsel and dragon fly nymphs found along weedlines in lakes and ponds, large mayfly nymphs and small green crayfish in streams and baitfish. Brown ones imitate hellgrammites and crayfish in streams as well as all manner of large mayfly and stonefly nymphs in streams and brownish baitfish like sculpins.
The 2 most popular colors for buggers are probably black- (with black tail and body and black hackle (grizzly hackle) and olive (with olive tail and body and olive hackle sometimes black or grizzly hackle. Brown buggers might also be a good idea for your smallmouths. (brown tail, body, and hackle).
As far as other patterns, I'd try and buy materials for 2-3 other patterns at a time and tie a bunch of them before moving on to the next pattern. Where you start is up to you, and depends on what kind of fish you want to chase first. Here are some suggestions with links from Charlie Craven's excellent site.
For trout some simple nymphs like a Pheasant Tail Nymph on a size 16 2 extra long nymph hook and a Hare's Ear Nymph on a size 14 2 extra long nymph hook are excellent choices. Both teach core skills that you will use on other patterns, and use basic materials that you can use to build up your inventory of stuff. Both patterns will also catch bluegill as well as trout.
Pheasant Tail Nymph Charlie's FlyBox - Colorado's Best FlyShop and online Fly Tying Tutorials
Gold Ribbed Hare's Ear Charlie's FlyBox - Colorado's Best FlyShop and online Fly Tying Tutorials
For smallmouth, you could add a bucktail or two, perhaps chartreuse and white, a length of beadchain or some 1/50 oz dumbbell eyes and some Pearl Krystal Flash and some size 4 or 6 standard length hooks to tie some Clouser Minnows
Charlie's FlyBox - Colorado's Best FlyShop and online Fly Tying Tutorials
You could also use your size 6 or 8 woolly bugger hooks and add some braided mylar like Diamond Braid for a body to make simple bucktail or marabou wing streamers for smallmouth. Here's recent thread with some info on making them as well as some simple foam spiders for panfish:
Patterns for a new Central Florida fly tier
Good luck and keep asking questions!