I just got a new (used) Peavey Delta Blues amp. I use a few different pedals but this is the first amp I've ever owned with an effects loop and have no idea which pedals I should put in the loop and which I should leave out front.

My current pedal chain is:

Guitar->Planet Waves Tuner->Vox Clyde McCoy Wah->Doobtone Microbuffer->Maxon OD-808 Overdrive->MXR 10-Band EQ->Fulltone Ultimate Octave (Fuzz)-> MXR Phase 90->H2O Chorus/Echo->Amp

Would appreciate suggestions/comments
There are no definite rules, but I would just put the phase and the H20 in the loop. The EQ and the fuzz could potentially go in the loop, depending on your preference. Most of he other stuff is usually put before the amp.

In very general terms: tone shifters like dirt/OD/Boost, compression, wah go before the preamp, and modulation or timed effects like a phase, chorus, delay, reverb are often used in the loop. There are plenty of exceptions, and you'll figure out what you like as you experiment, but that's a good place to start. There's also nothing wrong with not using the loop at all, especially if you mostly play clean. Lots of amps don't have a loop and work just fine with pedals up front.