IE6 compatibility help

hi, i'm sort of new to web design. i used to do a little back before CSS and now i'm trying to learn more modern techniques

i'm having problems making pages IE6 compatible. they look perfect in firefox/safari/IE7, but in IE6 there are always small layout problems -- like small spaces where there should not be spaces and little things like that. my pages validate in XHTML and CSS, but i seem to need to just figure out IE6. looking for maybe a guide or tutorial on why IE6 sucks and how to fix it

thanks!