Help with tutorials/ where to start

Projects General Guidance
7

Well I feel like i have a decent start on my timer. I do have a couple of very simple questions. I am using a Duemilanove board and,

  1. If im to hook 12v automotive power which will vary a little when alternator is charging 12.8-14.6, would this hurt my board and if so would a resistor be good enough to bring voltage to correct spec and/or what board would you recomend that could handle the fluctuation?

  2. can i energize a std 12v relay with power out from board or would i need a transistor?

Thanks
Again

I havnt started my temp controller yet but plan to get there very soon