Although this list doesn't have many illustrations, it may help you identify some of your US postal cards. Just keep in mind that values listed are retail and generally higher than even the Scott catalog uses, so you have to take it all into consideration:
http://www.brookmanstamps.com/Brook...USPOSTCD.pdfAlso, if you prefer not to purchase a Scott Specialized Catalog due to cost, the USPS has a Postal Service Guide to US Stamps that includes postal card listings, although not as detailed as that shown in the Scott catalog. It is usually available at larger post offices for $20 or you can order it on-line.