Buy/trade for mine. Majority come from members here but some come from Jann's Netcraft also. I go by a couple ideas when getting jigs......
-What fish you 'think' you will catch on them -
Heavier wire hooks in bass and walleye jigs. Crappie jigs can use larger size, but thinner wire hooks. Bluegill/perch jigs i like to use small hooks but i personally prefer heavier hooks for them since i use pliers/forceps a lot for deep hooked fish and don't want to break the hooks.
- Where & how you will fish them -
The heavier the head means you can cast farther and also get deeper. But that also means you may have them getting hung up in weeds/rocks. Flat bottom shaped jigs can help glide up and stay out of bottom snags. Flat sided jigs will cut through the water easier and go deep easily in current. I personally also like using jigs that have the hook eye a little angled to the front since the majority of my fishing is done by casting and not all that much sitting in a boat and fishing straight down.
- What you plan to tie on them or what type of plastic trailer -
Again, a lot of this is simply my own preferences. Jigs with tied bodies (w.buggers, chenille wraped, dubbing bodies) use jigs that have no lead collar and everything is tied right on the hook shank. Bucktail, kiptail, craftfur and most thread neck jigs i like to tie with a lead collar on the jig. Either cut off or flatten the lead barb, can also use ball collar barbs as others have mentioned. Plastic trailers can be hard to choose a good keeper style to not tear up the bait.... so far i like the wire keepers or spring shaped the best.
OR..... Since you are most likely going to loose a bunch of them and need more anyway, get simple ball heads in the weight and hook sizes that will get you by. They will catch fish if you know where the fish are. K.I.S.S. (keep it simple stupid)

But what fun is that?!!