Which verb form is "leen" in and how is it different from lee and lees? Lee is the tu form right?
That was a great example of the conjugation of leer. I hope you don't mind me changing the format a little. It makes a bit more sense if you do your first, second, and third person singular, and then your first, second, and third person plural forms. Plus I've added usted and ustedes.
Yo (I) - Leo
Tu (you informal) - Lees
Usted/El/Ella (You formal/He/She) - Lee
Nosotros (we)- Leemos
Ustedes/Ellos/Ellas (you all/they) - Leen
Leer is a regular "er" verb. So, if you learn the pattern for "er" verbs you will be able to conjugate "leer" or any other regular "er" verb. Here is an explanation about "er" verb conjugations: http://www.davidreilly.com/spanish/lessons/basic_verbs/er_verbs.html
More if you want to read more: http://www.studyspanish.com/verbs/lessons/juster.htm http://www.spanishdict.com/topics/show/36
This is a helpful site: http://www.spanishdict.com/conjugate/
You can type in a verb and the site will conjugate it for you in many tenses. E.g., if you type in "leen" it will show you that "leer" is the infinitive ("to read") for that verb and "leen" will appear under the Present, after ellos/ellas/Uds. (3rd person plural). You'll see that the "tú" form is "lees".