Just started playing this game and was wodering if there is any general technique I should use with my fret fingering or strumming style that I should learn from the get go to help out when moving up to hard/expert?

Be sure to do the tutorial first - That will also pick you up an achievement. I'd play through atleast Medium. I also stand up when I play, I don't do as well if I sit down for some reason.

The general consensus is to place your fingers on the red/yellow/blue frets and move your index finger from red to green when needed. That way when you get to the harder levels you can use your pinkie for orange.

Also get comfortable strumming up and down. I usually strum down only and when you get to the harder levels the notes come too fast to strum one way only.

Just play a lot and get muscle memory built up, and find the style that works for you. Someone else's technique may not work for you at all. and definitely learn to "alt-strum" (strum up and down), it will be crucial on Hard and expert. Most people down strum until they get to a fast part, then alt-strum that. Definitely takes practice to do it in the right spped/rhythm. I know this beacause I still suck at it. :D

Also I wouldn't play on easy too long. Start playing on medium as soon as you can. And check out scorehero.com. Awesome technique forum there.

there is a whole thread dedicated to guitar hero, you'll probably find more info in there.