You can read any of them by pressing the 'enter' or 'return' key. By pressing 'q' you can go back to whatever previous screen you were on. For example, if you are reading an article and you press 'q', you will return to the list of articles in the current newsgroup. To exit tin, simply press 'q' until you have gotten back to the list of newsgroups, then press it once more to exit. Also please make note of the help display below the listed newsgroups which shows many keys that are useful.
Help is available at each level by pressing the 'h' command.
The 'M' command allows the operation of tin to be configured via a menu. Using tin is for reading and posting news to the Dept. of Statistics and Computer Science.