First, you need to ask your company if the relocation package is included as your income on your W2, and if that amount is tax grossed up (i.e., in addition to the relo money, company also pay you taxes you might incurr on the relo money, usually estimated @ your marginal rate).

If it'll be included on your W2, it'll be taxable income.  But if it's taxable income, you can claim tax deduction on moving expenses.  Check IRS publication 521 & form 3903 for items that you can deduct. 

Usually, if your relo package is tax grossed up, you may get a little of that money back on your tax return.  Especially if this is your first job & you may be in a lower tax bracket.