|Since people come to you with questions, here's one to consider: are you trying to help others or yourself? People who have a strong need to be liked often have a hard time saying "no."|
Either way, since helping others is preventing you from doing your own job, there are some steps you can take. First, remember that your current behaviors are rewarding the employees who come to you, so they are going to continue to do so if you continue down the present path.
In the future, try to play the role of teacher or coach when people come to you. Rather than doing their work, show them how to do it. This might take longer the first time, but there might not be a second or third time.
A more direct approach is to refer these individuals to people in the company who are actually supposed to be answering their questions. If you do this in a friendly and supportive way, contact the referrals in advance, and follow-up with the employees to make sure they received what they needed, the employees will not only continue to like you, but they are more likely to respect you and your time as well.