It all depends on your betta. Most of my bettas are good around other fish, but if you do try it, acclimate him slowly, and add him after you have added the other fish. Some sites, and even videos on youtube are a good reference when adding a betta to your tank. You should do A LOT of research before adding bettas to a tank. I would not add them to a tank with danios for example or other fast moving fish, or long finned fish such as guppies or other bettas (male or female). Make sure you do not overstock, as it stresses all of the fish, and the betta and fish risk fin rot and other problems. There are also a lot of sites that recommend what fish to keep them, with- even some threads on this site!
If you have any other questions PM me.