Accomplishing your goals is tough, so it helps to have some support to keep you accountable. On the other hand, using too many people as support can hinder your motivation, so find two or three people to balance between the extremes.
Spouting off your goals to everyone can hurt your chance of accomplishing them, but telling no one means you don't have anyone to help hold you accountable. Telling two or three good friends, and keeping everyone else out of it, means you get the benefits of being public and private at the same time.
J. Money of Budgets are Sexy explains how telling people can help:
Once people know what you want, it means you now have to *act* on it else you'll be fielding a lot of questions you'd rather not answer. Your friends naturally want to help you out, and more often than not it will spark THEM to share some of their own goals in return. Which you can then help return the favour. It's total peer pressure, but in a good way :)
On the other hand, make sure you keep your goals quiet to most, otherwise you'll risk accidentally losing motivation.
Tell People What You Want [Budgets are Sexy]