One of the most important things to consider before having a vasectomy is that it is a permanent form of contraception.That means that you cannot change your mind and that you have to seriously consider how you would feel if for example your relationship breaks down and you enter a new relationship in the future in which you will not be able to father any new children.
There are surgeons that perform surgical procedure to reverse the vasectomy but the results of these procedures will depend on different things. For example the technique used in the vasectomy is important because not all vasectomy can be reversed successfully. Also patients who had a vasectomy can develop antibodies against their own sperms. This greatly reduces the functionality of the sperm even if the tubes are successfully connected. So basically while it is technically and theoretically possible to reverse the procedure, the likelihood of having it reversed successfully and to father a child is not very good. You should consider this form of contraception if you have carefully considered all of these facts and decided that you would not want to have any more children.