What should I consider regarding recessed lighting above kitchen sink?
If you've got insulation in the ceiling, you'll need to get IC (insulation contact) rated fixtures -- they're also known as closed-can.  I have a small soffet built over my sink; if yours is similar, make sure that the fixture you select will fit.  Other than that, don't exceed the wattage for the fixture and you'll be OK.

EDIT: On second thoughts, use an IC rated fixture regardless of whether or not you have insulation.  Over a sink, you're likely to have a lot of steam and if it's an open-can fixture, the stack effect is going to draw much of it up into the space over the ceiling.