Ok. So i have a job offer that i just received(company A). It is a great opportunity however, i have a few other opportunities available as well and i am not sure how to handle the situation. I have a few questions.
1. I have a second interview scheduled for Thursday of this week with another company(company

which i am pretty sure will give me an offer as well. Should i alert them that i have received an offer? Chances are i will have to give the company that already gave me the offer an answer prior to then.
2. I have another company(Company C) which i interviewed with today that i also believe will make me an offer. They told me the next step would be a phone interview with someone who was missing from the in person interview and then a decision would be made. So same as the first question. Should i alert them that i have an offer and try to get them to make a quicker decision?
3. I am going to speak with Company A tomorrow. Any tips on negotiating?
I guess this is a good problem to have. Thanks in advance for the advice.