Schedule D Gains Problems

I have a TUGMA account that I established for my son to pay for some of college. He is in fact now not a minor, and I pulled out $3500 last year as a drop in the bucket for his over-priced education. In completing Schedule D, I have no idea what the "basis" is in the stock, and there is certainly no help from the Form 1099-B. And I also got 2 different 1099-DIVs (not sure why I got 2) and there is of course a "Total Capital Gains Distribution" number wheich as I understand would go on line 13 of th Part II of the Schedule D. Now, in this transaction I will show (on my son's return) $321 in "Total Capital Gain Distributions" on Schedule D. Why in the world do I need to show anything on line 8(f) in gain? And if so, who in the world do I calculate that figure? Thanks.