not sure how good of a comp u need but some ram should help
as for 2 monitors
Find out what kind of slots you have. Easiest way to do this is by opening your computer and looking. You most likely have 3 PCI slots(these are white and on the smaller side). Then above those you might have an AGP or PCIe slot(PCIe just came out less than a year ago so if your comp is older than that you wont have it.)
one of these would be brown and without a trianed eye you wouldnt really be able to tell them apart. So if you see one call up who you bought it from. You would want to use that slot if you have since AGP is twice as fast as PCI and PCIe is twice as fast as AGP
once that is figured out go to
www.newegg.com and buy a card that supports dual monitors let me know if you need help picking