1. Your wife is never your dependent.
2. You can file resident tax return as Married Filing Jointly. You will have to wait for 5 months to file your tax return till you meet the Substantial Presence Test (of 183 days) in 2009.
You will get standard deduction of $10,900 and exemptions for both of you.
You must both declare your worldwide income for 2008. If you have any foreign income, and on that income you paid taxes in the foreign country, then you can claim foreign tax credit. Read about H1-B tax filing:
Your U.S. Tax Return: The U.S. Visas