508 Guidelines - should we or shouldn't we? Well elitists might try to. On the other hand they are there to help the disabled view the World Wide Web with a variety of means, shouldn't we want that? This is a good link to read more on. (it's the government's online course about Section 508)
You only need check one or two things actually, such as making sure ALT attributes are included, correct MIME types for certain tags, good document organization, tables have to comply to certain rules, etc., It's not that difficult but then again, you are also NOT required to comply since you are not a Federal Institution. Only Governments need comply.
If you want to add a link in to check your validity, use the following: