Just to amplify Eddie's answer - JSA is included as income if it is Contribution Based (which I would guess yours probably is, as your husband has been working) but not if it is the means tested version.
If it is Contribution Based you should have had a P45 or something similar from DWP JC+ after you came off JSA & it will be the figure on that which will be the income to declare. It goes in a separate section of the form from your earnings figures.
When you have submitted the annual return you will get a final award notice for the 13-14 year.
Your payments for the 14-15 year will be based on your joint incomes for the 13-14 year but if you have reason to think your 14-15 incomes will jointly be significantly different from 13-14 you can contact the Tax Credit Office, give them your estimates for 14-15 & ask them to pay you based on those figures.
Make sure you check thoroughly all award notices & notify any errors on them - & make sure they are then corrected.