Call your bank.
You'll get the lowest rates if you go full-out and get a merchant account, and such. Plus you most likely allready have a strong relationship with your bank so it makes things easier.
Do you need the physical machines? If not, just get an on-line console (you pretty much enter the customers information like you would when you order something on-line, and the amount to charge their card for), which is much cheaper.
Expect to pay ~$300 or so in setup costs (without hardware processing gear), perhaps a security deposit for chargebacks (if with a bank, they'll have you put it in a CD most likely.. prolly somewhere around $1,000). Typical fees depend on the amount and size of the transactions. You'll prolly see somewhere around 3% or so though, for normal small-business type needs. More if you have lots of small transactions, and less if you have a few large ones. There will also almost assuredly be a monthly processor fee, of somewhere around $50.
You can of course go with a ccbill type place, that essentially charges for you. The customer doesn't see your name on the statement, and you get nailed with something around 10-18% transaction fees. NOT the route to go for almost any small business, save perhaps businesses that are selling access to sites (porn, heh.)
So.. not exactly cheap.. But the benefits outwiegh the cost for us at least.
-Phil