I stopped by Mint first. Mint has a custom credit card finder in the “Ways to Save” tab. By filling in your credit score, whether or not you pay off in full every month, and what rewards you are looking for (ie miles or cash back), Mint will filter in and give you suggestions.
The benefit is the ease of use and ability to quickly sign up. Mint notes which cards are sponsored and which are not. I find the system a bit rough on the eyes, but it is a good tool. I would use this as a place to get an idea of what is out there. The biggest downside is that you will get relatively few results and the how much you save system seems a bit buggy.
Next, I headed over to BankRate.com. The main credit card page at BankRate is targeted more on interest rates than rewards, but is also a good tool. Because I pay my card off in full every month, I don't worry about the interest rate. The site does let you filter by card type. This gives you a better idea of what is out there. I filtered in on cash back.
I don't want the usability issues of American Express or Discover, so I am really focusing on Visa and MasterCard. From here, I took a look at creditcards.com and MSN Money Credit Cards. I have also done a little asking around to see what people are happy with.
I will update you with part two of this post, the decision process, later in the week.