dude i know exacrly where you are coming from with this one,
im pretty sure that the guys on here will explain this better than i ever could so hopefully one of them will fill in the holes.
i'm just at this stage myself, i've been playing for 5 years and the blues thing fitted me quite well, i could play a few tunez and jam along with some other guys etc, but all blues based.
this had made me lazy. when a guy i know came over for a jam about 3 weeks back (we had never played together before) i dropped into my usual bluesy style while he seriously ripped into all these modes, it left me feeling lost so i asked him the deal with this stuff. it's difficult to explain really considering he only had about 1 hour but here we go.
do you remember all that doh ray me far so stuff at school well that by all accounts is a major scale and modes it seems are made from this.
he said to make it easier use the c major scale and start from there so that would be the Thick 'E' string starting at the 8th fret of course and play doh ray me far so lah and so on.
that would be the c major scale or "ionian" remember the shape you played.
now shift up to d on the same string and play the same notes
that would be the dorian mode. this repeats.
now this still meant jack shit to me however i remembered the shapes and tried to play them else where and found that they work not only across the frets but up and down the strings as well so if you are playing the correct key in virtually any position you just need to remember the next shape and bingo.
a whole new world opens up. i still play blues scales but now i add notes from other scales and it works.
this helps explain it better.
if anybody else can explain this better please feel free as i am totally not a music techie at all
good luck with the stuff. another guy to listen to with this stuff is paul gilbert some guy has done a wicked version of technical difficulties in the mp3 section this song to me just oozes scales (even though i can't get near it)