just plug in stuff, if it don't fit, it doesn't go there
if you got any questions, we are more than happy to help
I built mine, that I am using right now with no prior building experience also
just take your time and you will be fine
some pointers are
make sure you ground yourself before touching any components. (rub yourself against metal) or get one of those 3 dollar anti static bands
if the vga card don't fit, don't carve the slot to make it fit
make sure everything is plugged in firmly
got questions? ask! this forum is probably better than any technical support you will get from dell.
you have given us your budget, how about the size monitor you want?
big price difference between 20 inch and 24 lol,
bigger monitor= less $$ for your computer components