I have sickle cell anemia. Are there any precautions I should take before dental work?

Not usually. It is important to let your dentist know, but most procedures don't have a major impact for sickle cell. Procedures that involve more bleeding would be of greater concern, things like extractions, dental implants, etc.
Generally no. Sickle cell disease can affect how well your blood carries oxygen. The only instance i see is if you were having nitrous oxide to help you relax for a treatment. Most offices that administer this also do a great job of monitoring you.
Not realy. Since these new guidelines came out last year, our sickle cell center no longer routinely recommends antibiotics for dental work for sickle cell patients -- only for selected situations local anesthesia rather than conscious sedation or general anesthesia. All of these concerns are greater for children with hemoglobin ss and hemoglobin s-beta-zero thalassemia, than for those with other types types.