Hey Megan - Since we are both Hoosiers, I thought I'd throw my professional opinion out there! (I'm a DDS in Pendleton!)
The White Strips do work well - but the over-the-counter ones are fairly temporary. They will look brighter while you are bleaching, but they will go back to 'normal' fairly quickly - even the Premium ones. There is actually a system of White Strips that can only be "Prescribed" (ie sold) from a Dentist office that works even better and does last a little while longer.
Crest has spent a lot of time & money researching their bleaching, so you can feel confident that it is safe as well. (Do be careful with some of the off-name bleaching products) The stronger the percentage of bleach, the more likely you are to get some sensitivity though.
The White Strips will not work well on fillings or veneers - and not at all on crowns. It would be best to have a check-up before starting any bleaching - just to make sure that there are no cavities present, or they will be even more sensitive.
A lot of dental offices are promoting bleaching now - with new patient exams, yada, yada - b/c it has come down in price for the dentist - so you might actually check with your dentist before just assuming that you cannot afford take-home bleaching. The material that comes from a dentist office is typically stronger, safer, and will last longer.
OT - I would stay away from "in-office bleaching" - it looks neat on Extreme makeovers & those tv shows, but it is almost Never worth the money. It will look great for about a month, but you can get almost as good results with the White Strips (it just takes a little longer) and you will get much better results with custom trays & dentist-recommended take-home bleaching material!
OT2 - If you do get some sensitivity with bleaching, I'd recommend the Crest Sensitivity toothpaste or Sensodyne - something with Flouride and Potassium Nitrate in it!
Hope that helps - Feel free to PM me if you have any other questions!
IndyJammer, DDS