I Received 2 W2 forms from my employer as I worked for them in 2 differents states, DE and NJ. The DE W2 has my complete 2009 wages (Box 1 & 16), while the NJ W2 only has wage entries for Box 16, with Box 1 blank. Do I assume that Box 1 is equal to Box 16 for the NJ W2?

First - please verify that that Box 1 of that first W2 is approximately equal to the sum of the Box 16 entries on the two W2's. It won't be exactly the same, but it should be close. This will confirm that your employer is reporting the right amount to the feds (Box 1 of the first W2) and also to the two individual states.

You include the "state copy" of the W2 that has NJ State income in Box 16 with your NJ State tax return. The fact that it doesn't show anything in Box 1 is OK - NJ is only interested in your NJ state income, per box 16. You include the other W2 State form with your DE tax return, and the federal version of that W2 (the one that has an entry in Box 1) with your federal form 1040.