The next step is to either accept or counter the offers you have with a counteroffer of your own. I highly recommend going to your State Real Estate Department's website and reviewing the specific disclosures you will be required to provide the buyer upon sale of your home because not knowing any better does not remove any future liability you create by not disclosing. Here is a link to CA Department of Real Estate website demonstrating what you are looking for: http://www.dre.ca.gov/pub_disclosures.html#_Toc122939748

With State and Federal disclosures at your ready, you can begin negotiating. First make sure they are "real" offers. Are they preapproved? If so by whom? Get a preapproval letter. If the offer is legit, you have three choices, reject, accept, or counter. Most choose to counter which is where negotiating begins. Once you have submitted a counter offer all offer previous offers are considered void. Once an offer is accepted by either you or the buyer, you will be in contract - once in contract you will want to open escrow with a local escrow company. Do not look to the escrow officer as your personal mentor. Their purpose is to act as a mediator and anything you tell them, they have to tell everyone else.

This is a general breakdown of the process in front of you - but it is impossible to answer this question in full with all specifics - point in fact you are looking for a crash course in becoming a real estate agent, and no single wiki answer can provide that type of training and knowledge.

My advice if you are serious about selling on your own is to do serious research on your own. Get to your State's DRE website and spend the DAY there. By some State real estate books: Real Estate Principles, Real Estate Practice, Real Estate Law and use them as references. People sell FSBO to save the 6% (or so) in agent commissions - invest some of that savings into the necessary material you require to sell your home correctly.