Now here is a topic that is pretty popular in the dental office that I work in. The article linked above a good summary but I would add a few items:
1) I would start in the commercially available products (Crest/Colgate), if this doesn't help then ask your friendly dentist about at-home/in-office whitening.
2) To limit sensitivity with the stronger formulations, it would be wise to start with a desensitizing toothpast such as Sensodyne twice a day for 2-3 weeks *BEFORE* starting a whitening treatment plan
3)Have resonable expectations. Do not expect the "Hollywood" smile if you drink significant amounts of wine/coffee/tea or any other food or drink that are known to cause significant colouring of teeth. If toothpastes and the products whiten your teeth slightly, then chances are the we in the office will be only able to get a few more shades on top of that. Veneers or other cosmetic dentistry may a be more viable option.
Take Care as always!
Hans Skariah, B.Sc., DMD