This depends on scoring, starting lineup requirements, and size of your league.
You say this is a small league - so I'll assume 8 to 10 teams.
You should load up on RBs, due to the RBBC approach used on many NFL teams and injuries. Extra RBs on your team are always good trade bait, and are easier to trade, than other positions. Getting THREE good RBs will be a big bonus, but I would attempt to get about five good RBs, and about 3 or 4 more spare RBs!
Most NFL do not use the QBBC approach, so even if every team in your ten team league drafts THREE QBs, you haven't even drafted all the starters in the league, AND QBs are not very good trade bait in this type of league, because everybody has a good one, if not, great one!!
WRs. Even if you have to start three on your team, the league will only need to draft about 40 WRs, though they will draft more. There are so many WRs who do not get drafted, and perform quite well for a week or two, or half a season. You simply cannot load up on WRs, hoping to decrease the talent pool, because it won't happen.
I prefer Rbs too, but in some leagues, QB scoring is so high you can't afford to lose out on the top guys, so getting a stud RB and QB the first two rounds is pretty inevitable, but then I'd still load up on RBs and get a sleeper or promising rookie as third QB, if this guy breaks out, you have great trade bait for the teams that lack a stud QB.
Well different leagues have different systems. For example one of the leagues that i am in give points to QB's for completions making pocket passers like gannon and bledsoe far more valuable than scramblers mcnab and vick. This coring also makes Qb's more valueable in my kleague, but in most standard league RBs r far more important.
If a Tight End is REQUIRED in your small league, that may be the position to load up on (when realistic ... I'm not talking first or second round).
Why? It's the single skill position with no depth. If you have get two of Gonzo, Shockey, and Heap, for example, you are GUARANTEEING that a couple of teams will be without a decent TE. A few TE's are better than a #2 receiver, perhaps making it worth taking a TE in the 4th round (RB,RB,WR,TE). Tight End, IMHO, is the only position where you can deny the opponent in a small league. Your only other "weapon" is smart drafting.