Whatever Jim Kramer says, I do the opposite, the guy is a joke and doesn't give out real advice, maybe a few tidbits here and there, but overall I wouldn't listen to a word the guy says. He's the same guy that said it was a good idea to invest in Sirius Satellite radio and they haven't made a single red cent of profit yet. Ya buddy.
If you're smart, you'd be investing in mutual funds with a dollar cost averaging approach. Takes a lot of risk out of investing, but will net you the best gains over time.
And no, right now would not be a good time to buy because it's going to drop further. Just hold out a bit longer if you want to invest in stocks.