Don't buy anything yet. Wait and see if we are indeed heading for a severe down leg.
Google "online broker reveiws" and find one that suits you. I use OptionsXpress and I like them just fine.
If the Dow goes down again, stocks like JNJ, WMT, KO, CSCO, PG will be screaming buys. The question isn't whether or not GM will survive, it's what happens to their shareholders. Only allocate a very small portion of your money to speculative stocks like that. F is the best long term bet between the two, IMO.
Research, research, research. I probably spend 40 hours a week reading about and watching the markets. If you don't know what you are doing, you will go broke.
If you have any questions, you can post them in the sell, sell, sell thread and someone will answer. Of the regular posters there, I'm probably the least knowledgeable but I'll try to help you any way I can.