Optimization & Loading

Hi guys, I am pretty new to flash but have jumped into the deep end anyway.

I would appreciate anyones tips on great optimization and if anyone can give me a run through on how to load certain things at certain times, or not everything at once, etc? If that is possible?

How much does actionscript add to the end file size? I have a heap of actionscript being applied to about 10 or more cells in a row (in about 4 places) but it is all the same. Except that each cell tells the player to stop, so I guess I can't just have it in the first and expect the rest of the cells to know to use it can I?

Thanks in advance :D K.