I want to vote... I have a many questions

I have not registered to vote yet. Never really interested me. I did a bit of research on the nationalized health care plan, can't find whether it was passed or not.
Is there a good web site to find information on the debates and issues to vote on so that I can build a strong opinion? If it helps I live in Spokane, WA.
Can anyone explain the difference between the parties, Republican vs Democratic?
Where do I go to Register to vote?
How long before actually voting to I have to register?
When does everyone vote?
Is there just one voting season of the year or are there issues to vote on throughout the year?
Any other information would help a lot. I really don't know anything about any of it! Thank you!