Will you get W2s for both jobs or will the new one pay you on a 1099Misc? Better find out when you start.
If you get 2 W2s each job only holds out like it's your only job so you may come up short at the end of the year and have a tax due. So you should adjust the withholding to have more taken out. If you get paid on a 1099Misc, independent contractor, etc. post back for a lot more information.
