Preparing for the release of Diablo 3 will give you the edge over most other players and allow you to level up faster. Many people were lucky enough to get invited into the Diablo 3 beta most people did not (including myself). If you have not already done so, sign up for the beta access giveaways on Facebook and Twitter and make sure you have entered your beta profile settings in your Battle.net account. Even if you do not gain beta access, there are still plenty of things you can do to prepare yourself for the release of Diablo 3.
Most gamers already know which class they want to play in Diablo 3 based on their favorite play style. If you have not decided which class you want to play, you should do so before the game is released. It is hard to tell which class will be your favorite without actually playing them but you can find tons of information and videos about each of the different classes online. Read up on each of the classes and learn about their different abilities and mechanics. Once Diablo 3 is released, your not going to want to keep creating new characters until you find the one that you like.
Learn about all the other features in Diablo 3 like the followers, professions, runestones, etc. Learning about all the different features available before this game is released will make it much easier for you to get started. Many of the features in Diablo 3 were not available in previous games. Be sure to learn about the new auction house features that will allow you to buy and sell items using in game currency or real world money. You can easily find websites with screenshots, videos and detailed information about all of these new features.
Find a few friends to level with. If you have not already done so, find a few friends that plan on buying Diablo 3 and plan on leveling up together. The difficulty will scale with the number of players in each game but having friends to level up with will make your experience easier and more fun. Have your friends choose their classes before the game is released so that you can all level up together without having to start the game over. You can easily find daily updates and news about Diablo 3 and all the different features in the game online. Be sure to check daily for new information about Diablo 3 and prepare yourself for when this game is finally released.