I half agree with Tault_pohyu ...
yes ab is nice n short ... but gaining rep in av is actually more easily done, and subsequent ranks will increase quiker within heavy av playin Vs AB.
numbers game plain n simple :
although AV is way to long (was in once fer 6hours!!) ... theres plenty to occupy your time. form the outset you could gather rams (if youre alliance) .. this repeatable quest is very str8 forward an easy.
made easier still if ur hunter or lock : stand on the bank so you can see the rams - put pet/minion on attack (aggresive) .. once he tags the ram, put him on passive, he runs back 2 you, ram follows up the hill .. charm, an hand it in... otherwise ya hav to grab a ram, go all the way around an over the bridge...
or you could do the mine repeatable quest (10 supply crates)
or you could engage in battle ofc
Also : to increase ur rep.. get u an ur guildies to collect the handable in bits over say 1week... then all join together - an hand in together as a team
hope this helps.
PS: AB rep will go quiker if your guild does it (on ur on ts).. random grps suck!