Should your choice be guided by the attracting joining bonus offers, promotions and other enticements? For the beginner it could be an incentive. There are online casino players who provide with money themselves to encourage you to take up online casino.
Should you fall for the bait?  In arriving at a deposit decision you should keep in mind the unwritten rules made by various online casinos, and among them include wagering and cashing out of the bonuses. You need to be finding out the extent to which this is done by the online casinos. You have to find out which are the games that have unhindered access and contribute the bonus as and when you win it in the first instance instead of it being staggered over a number of games. If the bonus is linked to staggering, it means that the website is luring you with bait and the intent is not fully honest. The casinos may allow you to play only for one hour with the bonus money that you may have won and subsequently may have put a system of restrictions. You should try to find out the deposit options, which are as per your needs.

If you are a beginner, the online sites even allow play with a deposit of $15 and also allow you to encash all your earning.