resize for print lab

Sorry for the noobish question but.
I've noticed when I goto my site most of my shots have to cropped for certain size prints. Is there a way to resize in PS to better accommodate the multitudes of different size prints available?

Both your cameras are 2:3 format, so you're covered for 4X6", 8X12", 12X18" prints. For other format prints, you just have to crop in PS.

Your various standard print sizes have various "aspect ratios", meaning differences in the ratios of the dimensions of the print. This is because of a long variation in film sizes, and then in "personal tastes" often arizing from using those standard print sizes.

For example, an 8x10 print does not "match" any of our digital camera sensor aspect ratio. Historically, it dates back to the use of 4x5 film, so that you could enlarge a pic from a 4x5 negative it could result in an 8x10 print. However, if you want an 8x10 print from your 60D photo, well, the 60D sensor has a 2:3 aspect ratio, and you cant "enlarge" that to 8x10, so you'd have to crop.

Just figure out what you can print without cropping, which for a 60D image can be done by multiplying the 2x3 dimensions, so a 4x6, an 8x12, a 12x18, and so on. Other "standard" print sizes will need to be cropped to the proper aspect ratio. Even though people do like 8x10 prints for "people shots"/portraits, it's the one "common" print size that has to be cropped more than the others (unless you print "square"!