My employee gives 50% discount for dependent's tuition - my daughters's tuition was $8000 so we will be taxed on the $4000. Where do I enter this information?

You say "My employee". I assume you mean your EMPLOYER.  I also assume your employer is the college that your daughter attends.  Tuition remission/reduction or discount is usually tax free and does not need to be reported at all.  Reference: page 8 of IRS Publication 970.  But, it may depend on how the college/employer  reports it to you .  Usually, the college simply reports $4000 (instead of $8000) in box 1 of the 1098-T.  Some will report $8000 in box 1 and $4000 in box 5 (treating the remission as a scholarship).  Either way, it's tax free and you just enter the 1098-T as received. 

 If it's reported on your W-2, it depends on where on the W-2 it is.  It's only taxable, if it's included in box 1 of the W-2.