The protocol is an appraoch to problem solving for Physics that was taught to me by my mentor. It works for most word problems in general.
1. read the problem
2. create a meanful diagram
3. determine the variables
4. assign values to variables (what you are given and what you know, and what you are looking for)
5. Determine what you are looking for
6. choose equation
7. do your algebra (to solve for the variable you are looking for)
8. substitue values into equation
9. complete the math
10 check sig figs and box or circle answer
Units are important and do count! You can use units and dimensional analysis to check your work also.
UPDATE: this was cross posted on my blog at http://educationaltechnologyguy.blogspot.com/2010/12/protocol-for-solving-physics-problems.html and a great discussion has occurred and some more links and resources have been added. Check it out for more physics problem solving ideas.