My bridal shower

is most likely going to be March 5 at the Olive Garden.

1-When do they need to send out the invitations?

2-Can they wait until January to actually start planning it or do they need to begin sooner?

That's my wedding day!!

They should probably book the restaurant now. I would send out the invitations mid-late January, depending on when they need a count.

i'd say try and book the restaurant now.. and then get some ideas for what they want. that way when they really all start planning they'll all be on the same page (if its more than one person planning). if its only one person.. that way the know what they need to get done and everything they have to accomplish so you have the best bridal shower ever.