Imperian has hundreds of help files to help you learn more about the game and how to play.
To roleplay means to play a role. In the context of Imperian, roleplaying means that you play as if you are your character. As Imperian is a roleplaying game, some level of roleplaying is required. When in Imperian, roleplaying is required anytime one is using any sort of public forum. These include public conversations, the news groups, citytells, and guildtells. Perhaps the best way to roleplay your character is to first create a coherent "life philosophy" for your character, and then follow that with your actions in Imperian. You might even want to write out a summary of your character's psychological makeup in order to make this process easier. For example, imagine a character named Valtre, who is a young male Tanari Taekyon monk. Valtre was raised a street urchin in Stavenn and was bitterly unhappy until he began following the way of the monk, and began to experience moments of inner peace. His primary motivation, currently, is to increase his knowledge and power, but his long-term goals are not those of domination over his fellow mortals. Instead, he seeks to rise to political power in order to help the beleaguered and down-trodden. He chooses not to worship any particular God, and his primary loyalty is to his race. He despises, perhaps irrationally, all Dwarves, due to mistreatment he experienced at their hands as a child. Finally, Valtre has recently discovered poetry and is given, somewhat pompously, to quoting his favourite poets at what others might consider to be inappropriate times, such as the heat of battle. With just this brief biography of Valtre, we have an interesting character with well-defined motivations and some indication of his psychological status. You would not find Valtre out slaughtering his fellow citizens, nor would you find him killing most sentients for no reason. He would be extremely interested in practicing his skills in order to master them, and would perhaps, as a hobby, hold poetry readings. While Valtre is open-minded enough to accept Dwarves in the same guild as him, he definitely would not socialize with them, and would likely be quite terse, though not overly rude, with any Dwarves he was forced to deal with. When roleplaying, try to make a distinction between the knowledge you possess as a player, and the knowledge your character has. Your character will not know everything about the world that you do. Act this out and you shall find the experience most rewarding.