Yichud Spaces
Following a Jewish wedding ceremony, the bride and groom retreat to a private room to share their first few minutes of marriage together. This aloneness is called yichud, and the room is called the yichud room. The guests should be far from the yichud room so that the bride and groom can have some quality alone time before greeting the crowd as husband and wife.
Some Jews of Sephardic descent do not have the practice of yichud at the wedding. For them, the chuppah, a talit spread over them, or the bride and groom's actual home serve this purpose. If you or your fiancé is Sephardic you may consider not having the yichud ceremony.
The Yichud Room
This room should be away from the crowd and have a lock on the door. There should be a place outside the room for two witnesses to stand or sit; this is actually an official part of the Jewish wedding ceremony, and therefore it requires witnesses. It should be completely private with no uncovered windows. There should be a table in the room and space for the bride and groom to eat their first meal as a married couple together and break their fast if they are observing the customary pre-ceremony wedding day fast.
It is a good idea to have the rabbi or one of your helpers check the yichud room to be sure it locks and is fully private on the day of your wedding. In ancient Jewish tradition, this was a time to consummate the marriage. Make sure the room is unlocked and open so you can go right in after the ceremony. Have the witnesses check to be sure no one is in the room and that there is food for you.
For couples observing the Jewish laws of family purity, if the bride has not been to the mikvah before the wedding, the couple would not have yichud in a completely closed room; instead, they would keep the door slightly ajar. It is wise to schedule one's wedding so that the bride can go to the mikvah a few days before the event.
For the Guests
There should be a reception room out of earshot of the yichud room for guests to gather while they wait for the bride and groom to reappear and make their grand entrance. Usually guests are served hors d'oeuvres and drinks and can schmooze with each other and wish mazel tov to parents and relatives in another room. This reception room should be large enough for guests to gather, though not necessarily to sit. You may want to have some tables set up for older relatives.
Another option is not to have a side reception room and instead to have the guests go into the main reception space to eat their salad and have drinks while they wait for the bride and groom to finish yichud. If you are not seeing each other before the ceremony and have not taken family pictures, you will do that after the yichud. Alert the venue of your need for a picture space for you to use after yichud. Most couples go back to the ceremony space for posed family pictures under their chuppah. Just be sure the management of your hall or synagogue knows not to take down the chuppah.

