applicable paragraph of section 508
(n) When electronic forms are developed online, the form should allow people using assistive technologies access to the information, field elements and functions necessary to complete and submit the form, including all directions and signals.
This corresponds to the WCAG section on “context and orientation information”. Proper use of the label element, including the for label, covers almost everything related to drop-down lists and check boxes. For instance:
<label for="mysel">Select a language:</label> <select name="mysel" id="mysel"> <option value="en-us">US English</option>
etc., or
<input type="checkbox" name="mycb" id="mycb" value="Reminders - Yes"/> <label for="mycb">I would like to receive email reminders</label>