By 'BOB' we mean: Boss Of the Bonus! As a new player, you have to learn a lot. Seduced by dozens cries as 400% sign up bonus etc ... you'll expect the max! Huge bonuses, so a lot of cash to grab. Nothing is less true! So the first thing to do: read the 'Bonus terms'!
What can be the case? Find out if the bonus is credited automatically? Or do you have to claim the bonus? Some casinos insist that, once signed up and made your first deposit, you either claim your bonus (a link on the "Promotions" page), OR you have to mail the casino support asking for the bonus. Another possibility is that the casino simply credits your account with the bonus, so called auto-credited bonuses! Do your homework before playing!
Which bonus to chose? We think, with our experience: do not claim a bonus! Why not? Because you can deposit the minimum deposit and no more (selfprotection). Agree, you play with your own cash but if you win some cash, you can withdraw (almost) without any restrictions. And if you lose, then you can still claim your bonus and have another trial. With accepted bonuses, you are immediately subject to wagering requirements. Always remember: a casino is not a charity! Free doesn't exist! Be the 'boss'.
When you check the TandC's of a bonus, watch out for restrictions or additional requirements for residents of certain countries. A lot is mostly happening. I.e. bonus is restricted to some countries (Russia, Poland, Denmark, Israel etc). Or some countries have higher wagering requirements!
Point 2 brings us to the next step: the wagering requirements! Often we just call them 'WR'. Most of the casinos will ask you to wager at least 15 times the total of the deposit AND the bonus before you can withdraw. Again: casinos are not charity institutions, so the WR often make it difficult (or impossible?!) to win some cash!
A few casinos, primarily those using RTG software, place a maximum cashout on any cash won using the sign up bonus. Typically this might be 10 times the amount of the bonus awarded. So, make sure you know if this rule applies.
A similar principle is sometimes attached to promotions.
Be aware of the fact that not all the games offered by the casinos, count bets towards the wagering requirement. Games like Roulette, Blackjack, Sic Bo and Craps are almost always disallowed. The same for Video Poker: a lot of casinos also exclude these games. Another restriction are the 'Slots only' bonuses.