I've done it very, very low level. 5ish or so. There will be some skin tasks that are completely beyond you, though. It makes for fun roleplay to get ahold of them. Don't forget to use SIGNAL to guilt people into helping you as well. Most times i've found they will assign you creatures level 2-15 or so, and that isn't bad. Every now and then they may ask for thunder troll scalps or skeletal warhorse jaws, but I found that to be rare.