Online Learning Usage Agreement Letter

We have recently made available to our organization some online learning courses. In order for individuals to access this materail each will be assigned a user name and password,a nd will have access for a set period of time. We would like to put together a letter of usage agreement for each user to sign. I know what need to do into the letter, but am unsure of how this letter should be put together. Does anyone have an example I could look at?