Will the proceeds count towards my AGI, Or will I just have an income deduction of the Long Term loss of 600? I bought stock years ago for 3,600 I'm selling for 3k

[VolvoGirl]

Yes the loss will reduce your AGI.  You enter the Sales price and the cost and Turbo Tax figures the net gain or loss.   You only pay tax on a gain and can deduct the loss.    The proceeds don't count.  

[Hal_Al]

Q. Will the proceeds count towards my AGI?

A. No

Q. Or will I just have an income deduction of the Long Term loss of 600?

A. Yes. 

That assumes you have no other capital gains. Capital losses are first use to reduce any capital gains (long or short term). Any excess (up to $3000) is then deducted against other income. Capital gains distributions shown in box 2a of a form 1099-Div are treated as  long term gains for these calculations.