Looking to potentially taking credit cards for payment - are there any concerns I should be aware of?

The safeguarding customer information should not be a huge concern, if you do not take posession of the credit card information (but check with your attorney) and process credit card payments through a third party like PayPal or a bank. You never receive the confidential information. You will only be responsible to ensure your third party is reputable. In addition to the costs related to accepting credit cards, please consider the costs and process you will need to develop to issue customer refunds. If not priced correctly, every refund will be a loss to you.

We started to accept credit card payments for our small survey business to help get payments in the door. We use a third party to help, but we also had to make sure we were in compliance with safeguarding any information faxed or emailed to us, so you want to look into that.
What caught us by surprise was when some companies with large professional services invoices due to us wanted to pay by CC as well. The fees were a big expense to us. Think through what this will cost you versus whether it will help get cash in the door faster.

My neighbor runs a small Gutter/Construction company. He started accepting CC's because he had customers willing to pay him on the spot when the work was complete; but didn't want to write him a check. He was looking at it from the perspective of why would I turn immediate payment away? He looked into an App for his phone and it's really quite brilliant. The vendor sends this little device that has a swipe built in; you plug it into your phone; swipe the card and he can even send the receipt directly to an email address (limiting the need to print a receipt). He says the fees are not crazy because he doesn't use it all the time and they are fairly reasonable with the percentage they collect. I recently went into a local seafood shop and they collected my payment the same way! Consider a cash flow perspective as well. The faster you can turn the work into cash is better (obviously as long as the vendor you use isn't charging ridiculous fees). Shop around; get different quotes - even check with your bank. Credit Card vendors are willing to be flexible. I shop our vendor every time my contract runs out. It keeps them honest. Good luck!

Credit card fees are, in my opinion, a cost of doing business. Most people prefer to pay with credit cards and most of my clients use AmEx, the most expensive of the major cards.

I've been with Avalon through Costco and their service is great and their fees are reasonable (relatively speaking). I use their virtual merchant service so everything is web-based, they hold all the customer information, and I can collect payment on the road through my iPhone. This set-up works very well for me.

If you're referring to "Square" Christie ... that was a complete waste of my time and effort. They are really only set up to do processing under $100. Anything over that, and my swipes were rejected.

There are very low fee options out there. Yes you should be accepting credit cards and the cost of any fees will be paid back by the reduced efforts to collect. If you have a banking relationship, contact your bank about merchant services, if you are using QuickBooks, there are some very very low cost options that Intuit offers.

There are lots of new entrants to the payment industry these days. Depending on the context for your business, it might also make sense to look into PayPal and Amazon Payments.