Gambling = sure much profit in second you can get but the risk is higher too, you can loss all
Trading = Need Skill for read the market
Invest HYIP / Ponzi = not recommended
Mining = need much balance to start and need maintenance fee
Signature Campaign = Good Start

I usually get bitcoin from 999dice giveaway each 2 hours get min. 10+ k satoshi,, and from faucet freebitco.in  ... In This Forum you can get from campaign signature too but i never try, because my stats was a newbie