In Spain we always pronounce "b", so you can pronounce "b" if you want and everybody will understand you. There are countries where people pronounces "v" or "b" so if you want to pronounce this way, we will all understand you too.

We don´t distinguish the sound, actually. Technically we should, but we don't. People would understand what you mean even if you don't pronounce it the right way.

Hola Kyle: In the past, the Spanish sounds of v and b where similar to those in English (vibran v and bilabial b), but nowadays they both sound the same (both bilabial). Thay are not supposed to sound different at all. Actually, if you travel to Spanish speaking countries you will sometimes find people who make the vibrant v, pretending to speak better Spanish than others, but that is actually wrong. The Spanish Academy of the Language (RAE) is very clear about this point. They sound the same.

I have always clarified it by saying V "ve de vaca y B de burro. V and B sound so much alike I use those to distinguish between the two.