I think bounty is an easy thing, in the first of all you should be an computer literate and know what is bounty. Now for you to choose bounty, you have to read about the bounty you want to choose and check or read the background read the whitepaper very well and if what is written suits you, you can now register in any of the bounty either you register in signature, twitter or facebook etc, you must follow it up till the bounty end and you receive you token that is all