From start to the finish, it can be hard to perfectly time all of the components of your event to ensure that it comes together seamlessly and smoothly for attendees, hosts and all those involved. Here is a rough idea of how and when to nail the timing of the various components of an event:
Scoping and seeking out venues; this should be done at least six months in advance, and giving yourself lots of time is key on this one. Thought should go into this process, and it is much more enjoyable when it is not rushed.
Getting a quote and a contract; once again, give yourself enough time to know and understand what you are getting yourself into. Read the fine print, ask the professionals and sign the contract with full confidence. This should really be done six to eight months out, (at least), to give you peace of mind that you have a site locked down.
Checking on the venue; going back periodically with different ideas and to varying stages of the event planning process keeps your thoughts on track
The event; set up early in the day, or even the day before if possible, allowing margin for error.