In 2008 I live and work in LA. My wife lives and works in MS. I was wondering how we are to file our state taxes at the end of the year.

Thanks

If you file joint return, then you will file returns for both CA (LA) and MS.
On the LA return, you are resident and your spouse is nonresident. Report only your income.
On the MS return, report income of your spouse who is resident of MS and you are nonresident of MS.