1. Ask for examples of the company's work.

2. How long has the developer been in business?

3. Do you communicate well with the developer, or is the language he/she uses unfamiliar and overly technical?

4. Ask for recommendations.

5. Don't select the highest bidder, and don't be tempted by the lowest bidder.

6. Does the developer offer to do a detailed development plan FIRST?

7. Does the developer follow through on small things?

8. Is the development company a good 'fit' with your company?

9. Is the company available for on-site visits?

10. What percentage of prior projects have gone into "production?"

General Tips:

Find a developer who is willing to put EVERYTHING in writing.

Find out WHO will actually be working on the project.