Yeah, if you're new, stick to agencies. Google is your friend: seduction-unlimited, ClassChoice, BOA, IslandsFinest....
For Indies, check here for reviews. Avoid any that say "party" in the ad or have signs of drug use; unless that's your thing.
If you're looking at an ad and its too good/bad to be true, it probably is. Use google image search or tineye.
Lastly, unless you're bold, avoid incalls at hotels/motels. And don't bring a lady unless she's vetted to your place.