First, creating a credit card process yourself won't be easy and won't be cheap. Most webhosts charge extra for using SSL. It would be easier to get somebody to do this part for you.
OK, if you want some tutorials for building a shopping cart etc. just type something along the lines of "shopping cart tutorial" into Google. There are tonnes out there. Also if you know what language you'll want to be using (e.g. ASP, PHP etc.) add that into the search too.
Also there are bits of software out there that can help you do this too. I'm guessing that DreamWeaver or Frontpage will probably have wizards to help you do this. Also check out this page -->
http://www.actinic.co.uk/ . Actinic provide software to help you get an ecommerce site up and running quickly and easily.
Finally, as an alternative to PayPal, check out
http://www.worldpay.com
Hope that helps.
Lee,