What do you need to know?
Okay, if you participate in your employer's 401K AND your AGI <$90K you can contribute $5K to your IRA. Same goes to your spouse but remember if you are filing joint return AND your spouse also works your AGI is COMBINED. From $90K to $110K you can contribute a %. Above $110K: nada, zip.
Similarly if you DO NOT participate to your employer's 401K then use the second table.