Be sure to determine if the type of information you are protecting is something that could truly jeopardize your company if it got out. Identify the time duration. Like it or not, you cannot protect some business secrets forever. At some point even your best information may become stale and you won't be able to sue over its loss. Consider the penalties for violating the agreement.
Penalties can include injunctions or monetary damages.
These may vary according to the jurisdiction you are under. California tends to be very strict on non-compete agreements, but other jurisdictions are more lax in enforcement. Consider your existing employees. You may want to include a clause about protecting your current employees from being raided by former employees looking to take over your business. As with most legal matters, it is important to remember that non-competition agreements work best as preventive medicine.