When should you or are you going to do room blocks for OOT guest?

I don't have a definite answer to this question but I would say the sooner the better especially if your wedding is surrounding a holiday weekend.  Also keep in mind depending on the time of your wedding most hotel rates only are guaranteed for a certain amount of time for the following year.  You can try calling now to see if  your dates will be available with rates.  A lot of hotel require a minimum of 10 rooms per booking.  I was going to do this but I told FI I'm only checking for my OOT guest because he want his family to be in the same rooms.  That is his business. I wish I had more of a better answer.  I used to work in the hospitality industry but this is all I have as far as wedding.

I'm not block booking. I have given guests details of all the hotels in the area and I'm letting them book their own, some of them are staying for 1 night, some for 2 and some are making a vacation of it and are staying for a full week so I'm letting them sort it out for themselves

That makes sense Canooknic. I have about 30 of my family members coming from Chicago, this will be their first time in NYC so I want to make it as easy for them as possible. They are also thinking about chartering a bus to get here so finding a hotel with bus parking is going to be a little difficult

Here is a website I found with great question and tips

http://littlewedplanblog.wordpress.com/2010/01/20/finding-room-blocks-a-guide/

When I went to check out hotels all of the managers told me to block out by November (my wedding is in June) so about 6-7 mo out? I think it also depends if you are getting married in a metropolitan city and if any community events will be going on during that time.