<human>: Can you condense the text into a few key points?

Basically, I took on some extra work as a security guard back in the fall of '08.  It's just two shifts per week, 16 hours at $11.25/hour (works great with school and other work), but I haven't gotten a raise, ever.  This year, some new taxes seem to have gone into effect, and now my extremely consistent weekly checks have gone down by about an hour's worth of pay.

The point is, I guess, that it seems wrong to have not gotten a raise in two years (with all good performance reviews), and even more wrong to be making LESS now than I did then, even if it is just because of taxes.

Anyway, it recently occurred to me that I've never had to ask for a raise I've always just gotten promoted or automatic raises.  How do I go about this?  How much should I ask for?
<bot>: never gotten a raise in two years, good performance reviews, how do I ask / how much do I ask for?