setting up a network HELP

ok so i got a laptop for university
im tyring to set up a network so i can load my notes and stuff from school onto my desktop and vice versa
i figured it would be easy
HA
so heres the situation
my dads desktop in the next room over is has the hardline for our internet and a router etc. his is like the master computer that provides the internet for all other computers in my house (my desktop connects to it, as does my laptop). his computer is running xp, and both of my computers are running vista
so i screwed around with a tonne of crap on my desktop and laptop to try and get a network going. the situation is a friggen mess. all computers are on the same workgroup, and i got a few other networks going for my laptop and desktop, but i get no results no matter what i do. except for the fact that my desktop will show up under MY NETWORK or w.e on my laptop, and my laptop will SOMETIMES show up on the desktop under MY NETWORK. if i click either however, it asks for a username and password, which to my knowledge i havnt set up. ive tried logging in the all that blank, and it wont let me. i also got an ethernet cable to hardline the two, and that hasnt done anything either. i tried setting up an ad-hoc or w.e, and it still didnt work.
i dont know a whole lot when it comes to this internet stuff, and ive tried to look up a bunch of threads and crap and i either get lost or confused or something doesnt work when i follow a tutorial or w.e
could someone help me with this PLEASE or provide me with an idiot-proof thread/tutorial on how to do this????