Botox treatment effects

I feel strangely that it's time to decide whether or not I should get botox. I'm thinking of getting botox not for cosmetic reasons, but to make my social life easier.

Question here: How long does the effect of Botox last? My friends say it lasts about a year. Is that true?

And are there any precautions to take after getting Botox? I'd like honest advice from those with actual experience.