I would look for routes other than feats. Unless you're playing just a pure fighter, you won't be getting enough feats that it's the best way to pump up an archer. Prestige classes are a better route.
Both Deep Woods Sniper (MotW) and Order of the Bow Initiate (S&F) add a large number of VERY nice abilities to an archer. The Forgotten Realms book "Silver Marches" (IIRC), has a class called Peerless Archer, which is probably over powered. If you still have your heart set on using feats, most of the class abilities could be converted to feats.
Particularly if you go the DWS route, do NOT under estimate the value of Improved critical, especially if you get a Burst effect bow. A DWS can get up to a x5 crit multiple and with a burst bow you'd get another 4d10 stacked on top of that.
Multi-shot is clearly one of the best feats for an archer. Since with one partial action you can get up to about 4 attacks in (2 at +6 bab, and 1 more per +5 additional bab). It is only against one target, but usually that's all you'd be shooting at. It actually makes Shot on the Run extremely useful (as opposed to nearly useless). So Multishot and the SotR chain will eat up 4 feats (MS, Dodge, Mobility SotR).
Some other non directly Archery related feats that would still be extremely useful are Leadership and the Riding feats.
Leadership can get you your own personal caster to buff you with GMW, cat's grace, bull's strength etc... Probably over all the most useful feat as a result.
It can also be used to purchase an exotic steed (griffon, unicorn, pegasus etc...), which adds a considerable amount of personality and flavor to a character. Also as a steed is doing the movement, your character can effectively get in a full move and still get off a full attack action (read the mounted archery section in the PHB). Which is also where the mounted combat feats come in.
