The Elder Scrolls IV: Oblivion/Trainers

Trainers

Marksman
Apprentice Level
 * Elda Dark-Heart in Regner's house on the south side of Bruma
 * Shameer west of the Great Chapel of Julianos in Skingrad

Midlevel
 * Pinar Inventius in Anvil
 * Reman Broder southwest corner of Skingra

Expert
 * Must have level 70 Marksman and Disposition of 80
 * Talk to either midlevel trainer who will send you to
 * Alawen at Troll Candle Camp east of Anvil
 * Visit Troll Candle Camp between 10pm and 4am.
 * You may have to wait later than 10pm if she was on a long hunt.