The internet has a vast store of resources available that can help you in regards to your lessons, whether you are a teacher or a student.
Activities with Legos - www.legoeducation.us/activities
Lists of Resources on a wide variety of subjects – www.thefrugaleducator.blogspot.com
Lesson Plans and Worksheets -
Free Online Books (mostly public domain books) -
Disclaimer: These recommendations are purely my own, based upon what I personally have found helpful.