Roulette is not a complex game, but there are a few things every player needs to know about betting in Roulette. Primarily, and as stated above, do not touch your bets once the dealer has called for final bets. Whether you are playing online roulette or in a real casino you will not be able to make changes even if you suddenly realize you made a mistake. There should be lots of time to place your bets so relax and be decisive.
While not an issue when playing roulette online, each player will be given a different colour of chips to help distinguish the bets of each player as there are often quite a few at any given time. Each chip will generally have a set value relative to the table minimum. If you need a different value for your coloured chips speak to the dealer.
It is common to be permitted to spread your minimum inside bet across a variety of number options and in different amounts. However, for your outside bets you will usually have to place at least the minimum on any given option. If a 0 or a 00 come up all outside bets are lost.