Am I reading things correctly when I read that if I were to put $8k into an IRA (married) before Tax Day, that I can claim that amount on my 2006 tax return to lower my AGI?
If you put it into a traditional IRA you can deduct it. I think it is $4000 for you and $4000 for a spouse. At a certain age that increases. The main difference is you will pay taxes on it when you take the money out. However, a bigger balance so you earn money faster.
A roth will let you put money in after you pay taxes on it now. the benefit being when you take money out at retirement you don't have to pay taxes on it.
I prefer the roth because I plan to have more income when I retire than now so I want to reduce the tax burden later.