A.,
Here's my 2� (for what it's worth):
I don't like the idea of having debt or paying someone else to use my own money, but I have two credit cards - one I using for 98% of crdit card purchases and the other for those purchases I can't make with the first.
While the airline miles cc's seem attractive, unless you travel often and are getting miles another way, I don't think they pay off in the long run.
My primary card is a Discover card because they give you cash back on your purchases. This is of more benefit to me than "gift points" or "miles". Discover sometimes has promotional interest rates, but these are only for some initial period. Their rates are high (I think because they give you cash back). However, if you don't intend to carry balance, the interest rate is irrelevant.
Not a fan of credit cards before, either, I got one when I first needed to rent a car some 10 or 12 years ago. However, now that I have my Discover card, I use it for every purchase I can so that I can get my cash back. Of course, I don't carry balance on it, I use it the way I would use cash - only if I have the money for the purchase. For me, this works great.
I also have a Visa (which pays some amount money to one of my charities for each purchase I make on it) because not everyone takes Discover.
I understand that there are Visa's and Mastercard's that pay cash back now, too. There weren't any when I got my Visa.
If you are needing to carry a balance, then just look for one that has a low interest rate beyond the promotional period (unless you can pay it off during the promotion, in which case just get the best promotional offer you can).
If you google "credit card offers" or something similar, you should find several sites that have cc offers listed and you can compare. Also, check out Discover's site (www.discovercard.com).
My Visa is with MBNA, who allows you to make online scheduled payments (as does Discover). Their website is MBNA.com and (I just check their homepage), they now have a cashback card. You can see their current offerings there. I have no complaints against them. In fact, when I first set up online payments, I somehow did it wrong and it didn't post. They were very helpful in getting it set up correctly and waived all late fees. They have a secured setup for getting the online payment going and you can call and do it over the phone so that you never have to transmit your bank info over the net.
I hope that wasn't too wordy and you found it helpful. If you have any questions, please let me know. I'm not a financial wizard, but I have been around the block a couple of times. :-)
Hope that helps,
P.