Get a set of dice. It's $4 or $5 for a full set (4, 6, 8, 10, %, 12, 20) at most card or comic shops. Try Things From Another World.
The three core rulebooks are also a must-have. Any 1"x1" square grid works for a map. Hell, you actually don't need a map, but they're helpful. If you don't want to shell out for a grid, you don't need one. You can just get a "soft" tape measure (like what you use to take body measurements or measure diametres) and draw out the map on a large piece of paper or a whiteboard and use a universal scale (1" = 5' is pretty standard). Miniatures aren't necessary, but they're nice to have. Mage Knights pieces work fine if you have them lying around. If you want to be really low-budget about it, you can just use pieces of cardboard. or small numbered gambling chips.
Aren't you friends with my sister? We can probably lend you our spare 3.5 DM Guide and 3.5 Player's Handbook. (we have two of each of those ones)