Cookie

Wow!  Cookie is a new website I recently came across.  It is a goldmine for teachers (and parents) of young kids between the ages of 3 and 8.  It has online games, short animated videos, worksheets and stories.
They are all organized into different categories like language, math, science, puzzles and many more.
For a teacher it's a great place to quickly find a game or worksheet for students to work on a specific skill being taught.  Children can work on sequencing activities, phonics and alphabet activities, counting and math activities, personal hygiene, months of the year... a very wide array of themes.  It's worth a look!
The games are great worked on a computer alone but are also great played on a smartboard.
http://www.cookie.com/

Math Worksheets

I am always looking for good free websites to make quick extra math pages for my students.  These two sites offer a new random assortment each time when practicing addition or subtraction.  I go to them often.

http://www.math-aids.com/  : has a big assortment of worksheets including addition, subtraction, multiplication, division, order of operations... much more than I can list on this blog.  It is definitely worth a look.  What I most like about it is that after you enter your parameters (for example no number bigger than 10 or no carrying... etc) it generates a new random worksheet each time.  Another amazing thing is that it is completely free!

http://www.mathworksheetwizard.com/ : is another great free website to use.  It is categorized by grade level and covers arithmetic, time, money and measurement.  It's another one I use all the time.