The developers at BioWare realize that groups want to be able to get in on the action as soon as they can, so the company is allowing official guilds to start forming right now. On top of that, the devs want you to be able to find a guild that fits your wants and needs before the game starts. A guild search and creation page was launched this morning on the official website to help you find the guild you're looking for or create one yourself. At this time, you can only join one guild, so make sure you pick the right one!
Search your feelings, let the Force guide your actions, then jump to the SWTOR guilds page now for more information.