Really not something that can be answered very well in a message board post. It can take quite a bit of time and effort. Really depends on the size of tournament you plan to run. Are you taking over an existing tournament or trying to establish a new tournament from scratch?
If you want a better answer:
Is this a new tournament or established?
What dates will it be played and what other tournaments are played on that weekend?
Is there a lot of competition for teams or will you be able to fill a tournament easily?
How many fields do you have or can you secure?
What are the upfront costs and who is covering those bills till the money comes in?
There are dozens of other questions but these can get you started and will determine the size of the undertaking you are getting into.