Back in the Bad Old Days™, it could be difficult to find a scanner that worked with OS X. The problem really wasn’t the scanner itself. The problem was the software. Manufacturers recognized that Apple had a much smaller market share than Windows – it was less than 10% even ten years ago – so the manufacturers didn’t think it was worth it to develop and provide OS X software. So sometimes it was difficult to find a scanner that would work with a Mac.

Check the OS Requirements for the scanner
Nowadays, even though it’s still a mostly Windows dominated world when it comes to desktop PCs and laptops, one market analyst says that in 2014, Apple will reach parity with Microsoft in terms of desktop and mobile sales.
(See 2014 is the year Apple market share catches up with Windows, says analyst – wait, what?.)
So in other words, these days, pretty much anything you buy will include Mac drivers on a CD in the box. Or, OS X itself will include drivers. Just check the technical specs of the scanner to be sure. There’s really a 100% chance what you want to buy will be supported by OS X.
I’d be more concerned with the quality of the scanner, i.e. the DPI of the scanner and the quality that you want from your scanned photos. Consider the type and cost of the scanner and think about if you also have 35mm slides to scan, or strips of negatives or prints themselves. Scanners have different capabilities, and you might want to get a dedicated 35mm slide scanner. Or you may decide a flatbed scanner will do everything you need.
As with any tech purchase, do your research Scanner buying guide 2 | PCWorld and check product reviews online, such as Flatbed scanner Computer Peripherals – CNET Reviews and Scanner Reviews | PCMag.com.
Or, go to amazon.com and other online retailers and see what people say about the scanner they bought. There are lots of resources out there for buyers, so it’s a good idea check into them.