On most laptops a RAM upgrade is (usually) straightforward enough, as there are (usually) fairly easily accessible RAM sockets, though you will have to remove some portion of the case - possibly lift up the keyboard.
Make sure you have the user manual to hand so you can check EXACTLY how to undo which bits to get at the RAM sockets.
You should be able to find the correct RAM module using the Crucial or Kingston Memory Finder.
USB - no way. You should be able to find a PC card (PCMCIA card) with a USB 2.0 interface - assuming you have a free slot. Check compatability before you buy.
SD