Study the terms of standard recording agreements. There are many helpful books on the subject written by prominent entertainment attorneys who have negotiated contracts for the industry's top artists. You can also learn a great deal about the basics of record contracts online for free. The more you know going in, the less likely you are to be taken advantage of.
Make it clear that you do not wish to sign a contract that will bind you for an unreasonable period of time. Contracts typically consist of several periods: an initial period, and one or more renewal periods. Three years, including all renewal option periods, is generally considered a fair compromise. Many record labels will try to get an artist to sign away as many years of their lives as possible. Should you find yourself bound to a label that isn't working out for you, it could ruin your career.
Be certain that the initial period of the contract term is no more than one year. After that initial period runs its course, the first option period begins. In longer-term agreements, this will be followed by a second, third, fourth, or even fifth option period.
Negotiate the required minimum and maximum number of master recordings that are required to fulfill your commitment for each period. This will generally be an album's worth of material, or a set number of songs. Do not let this be an open-ended clause in your contract; some record labels may set a minimum number of songs but not a maximum.
Insist that the agreement require the label to actually release the recordings you have made during each contract period, or at least a percentage of those recordings, in order to exercise their option to renew at the end of that period. Otherwise, your songs could sit in the vault for years and never see the light of day, while you are contractually bound to continue making recordings for the label.