IT USED TO BE that credit-card companies didn't care about the little guys. Now, fishing for new business, issuers are wooing small firms with big rewards and fancy perks specifically designed for entrepreneurs.

American Express, for instance, last month launched its SimplyCash Business Card, which offers 5% cash back on common small-biz expenses: gas, office supplies and wireless charges. Visa USA in September introduced Visa Signature Business, which has no preset spending limit and includes an online expense-management feature. And Discover jumped into the market this summer with its Discover Business Card, which comes with "PurchaseChecks," or fee-free checks that business owners can use to pay vendors who don't accept credit cards.

"We've seen a proliferation of business cards in the last year or two," says Curtis Arnold, founder of CardRatings.com in Little Rock, Ark. "Innovations seem to be coming out all the time that are targeting small- to midsize business owners."

How to sift though the sea of offers on your desk, especially when you're strapped for time? Here are answers to some common questions.

First, is it better to use a business credit card as opposed to a personal credit card?
Yes. Lots of start-ups rely on credit cards to get their businesses up and running. In the past, entrepreneurs were forced to use personal credit cards; carrying that extra debt from the business often hurt their personal credit scores. Now, it's easier to open a business card account — and that's the way to go, says Gerri Detweiler, author of the "The Ultimate Credit Handbook." "Business credit cards typically aren't reported on your personal credit report...and the rewards are pretty rich," she says. Keeping business expenses separate from personal expenses makes it easier to track your tax deductions. (Not to mention, you can write off the business card's finance charges and annual fees.)

Should I pick a business credit card based on its rewards program?
That depends on how quickly you pay off your balance. "The rule of thumb is, you don't want your rewards to cost you more than what you pay for them," Detweiler says. If you're quick at paying off debts, then take a look at the nice array of rewards out there. Business owners on the go may want to focus on airline miles or hotel discounts, while others might prefer cash back on office supplies, cellphones, Internet service and computer equipment. Some cards offer a discount for shopping at specific merchants, such as Office Depot, FedEx, Kinko's, IBM or Pitney Bowes. Don't let the rewards distract you, though: If you plan to carry a balance, choose a card that carries the lowest annual percentage rate possible (and pay attention to whether rates change after an introductory period).

Can I choose more than one?
Yes, and that might be a good strategy, advises CardRatings' Arnold. "If one particular card gives you enhanced rebates on gas — say 4% or 5% in gas rebates — and you spend a lot on gas, you might want to use that card just for gas, and get another for everyday rebates," he says. Or, choose a card with a rewards program for business expenses that you can easily pay off each month, and choose another card with a low APR for paying off other debt over time. A word of caution, though: Don't lose track of your plastic. "Cards are becoming more fee-dependent for their bottom line, so if you're not on top of things, you are going to be hit with a late fee," he says.

What else do I need to know?
As always, read the fine print (especially when it comes to introductory rates and annual fees) and do your research. Click here for CardWeb.com's December 2006 survey of business credit cards. Bankrate.com also has a handy tool for scanning the best offers. And while it's gotten easier for small-business owners to get cards, you'll still need good personal credit, as cards are issued based on the owners' financial strength.