Stanford Letters of Recommendation

I’ve tried looking up how you are supposed to put letters of recommendation on the Common App for Stanford, but I haven’t had much luck and am confused on the process.
When I ask teachers to write one for me, what should I ask? Should I just ask them to write a letter of rec. for Stanford, or inform them that it will be put on Common App, or something else? Are there any special steps that need to be taken to put letters of recommendation on Common App?

Bump

Use the common app to assign your two recommenders. In addition to their letter, there is also the Common Application Teacher Evaluation Form. They should be submitted online whenever possible. Stanford also allows an optional third (non-teacher, non-counselor) letter of recommendation.