good eq guides for newbies

I finally have all the parts of a remix synced up but the levels and eq sound retarded. can anyone recommend a guide in laymens terms explaining the basics? also, one thing I never understood...how good does a song sound before it gets to the mastering process? Is it usually pretty finessed eq-wise or does the engineer really bring all the parts together?

http://www.musicianstechcentral.com/library.html

I havent read any of it but you may find it helpful. I think you should try and keep the sound quality in check during every step, unless your paying an 'engineer' you'll be doing it all yourself, so save yourself trouble.. even if you were paying an engineer theres only so much they can do.