I have a Linksys Wireless router that currently broadcasts an N network. But I am looking to also add B/G to the network. So, Pit, my question is do I need to buy a router that does all three, or could I just add another to my existing setup, and if so, how would I do so?
You could add another router to your setup. Just buy the one you want and run an ethernet cable between either your modem and the new router, or your other wireless router and your new router.