I'd do up a decision-making matrix in excel for starters. Put the three ideas down the left and criteria you think are important on the right. Assign a value 1-5 of importance, 1 being not important, 5 being crucial/very important. I'm not going to do this for you but a couple would be:
5 - feasability (has it been done before, likelihood you think it would have of success.)
2 - Estimated initial returns.
5 - estimated middleterm returns (after a year imo)
3 - estimated long term returns (2 years +),
3 - startup costs and asset requirements (do you have what you need to begin, will you need staff/management?, how much money will you need to borrow)
3 - your interest in the ideas field (obsession and a genuine interest in a business product/idea can go a long way.. one might look better on paper but if you find another one appeals more to you then you should pick it).
4 - do you have the neccessary skills/experience/contacts needed
You get the idea, pick criteria that you believe are important and assign an importance number (To figure out how important they are you might need to do some research on the success/failure of similar products)
now you fill out the table, say your first idea is 'turn the DJ Bible into a real publication' you assign a 1-5 on how well it achieves each criteria. For example, 4 for feasability, 4 for initial returns, 3 for middle returns, 2 for long term returns, 5 for startup costs if you had the rights to the material

and the money needed, 2 for interest if you dont really find DJ stuff interesting, and 1 if you have never written a book and dont have the neccessary contacts for the last criteria. Remember when assigning values to not be too optimistic. So now you total it up mulitplying the criteria importance value by the other number and come to a total of 20 + 8 + 15 + 6 + 15 + 6 + 4 = 53
Do it for the other 2 as well and the one with the highest score is your best bet.
I hope you find this useful, took longer than i expected to type up. You should also do some other things in conjunction with this to decide but without actually knowing what your ideas are i cant offer advice on that yet.