Well, this is going to end up a dead thread unless we can find a host. I'd also like to find someone who can explain to me how bigger meets get set up, from sponsors to venues. I'd like to do that if it was at all possible here in Texas.
Bigger meets are sort of a part time job. You need a few spreadsheets to track who is interested, who is confirmed to attend, who is bringing gear, how much gear, who has paid, who hasn't paid. You also need a floor plan for your venue with tables set up in an intelligent way to make it easy to walk around, but also maximize your table count by arranging them back to back in the center and around the sides in a single row. Once you have this, you need to label your tables (I split each table, because most people only bring half a table's worth of gear), then you need to assign people who are bringing gear to the tables, and in doing so, keep track of what gear is being displayed at each location, so you don't end up with 5 tables in a row of HD800s or Schiit stacks.
Vendors are mostly via email, but some of the more forum friendly ones you can contact by PM here on HF. Basically you state who you are, what you are planning, when and where, and what you expect to have for attendance. We had a few out of town vendors at the 2014 meet that probably felt a little disappointed in the attendance for their effort of attending, so if I am hosting, we might limit to only local vendors, of which there are more than you'd think! Sometimes you'll find vendors who can't attend but might send a demo product or two for you to show and be responsible for, and then return after the event. Matrix and Violectric has done that with me in the past. So once you know which vendors are attending, you then have to decide if you want them segregated or mixed up with the member tables. I've done both, and despite the lower turnout of the 2014, I think the mixed up model works better. This gives the vendors their own space to do their thing without competition brushing chair legs. Also, vendors with the most gear have the most boxes, so putting them in the corners of the room really helps them, especially if your outer ring tables are right up against the walls.
Dealing with the venue is pretty easy, but you need to pay attention to details. A place like Norris is mostly about parties and wedding receptions, so they are in it for the catering and additional services. There is no outside food allowed because they provide that service, much as with a movie theater. Catering with them is extremely expensive, while the rooms are reasonable, so to anyone but us, their rooms look cheap until you add services. The contract for the room is simple and the staff is helpful, but it can be difficult to get pictures/video of the room you are reserving if you are hosting from out of town like I was. Having a local HFer be able to take video of the room, or being local yourself and inspecting it in person helps you set up your floor plan as mentioned above. Most contracts require a down payment of 1/4-1/2 then the rest due a month or two before your event, so be ready to be on the hook for the entire room until the event.
I found it helpful to have a list with me the day of the event showing who paid and who hadn't, leaving space for unannounced attendees/friends of those who already signed up. As a host you need to be the first to arrive and will probably be the last to leave. Our meets were 9-5 if I recall correctly so I showed up around 7:30 and left about 6, it's a long day. The host gets some time to hear gear, but you get interrupted quite often by people showing up who need to be checked in. You can relieve this to some degree by having a 2nd or 3rd person taking watch at the check in table, if you trust them to handle the money (if your event requires members to help pay for a room). You also need to keep an eye on what is happening in the room. You probably don't know everyone there, so watching out for theft or damaging accidents is a good idea. As host, you should mediate any accident that could cost money to settle.
Host tips:
Bring at least one large roll of 2" gaffing tape. This is a type of masking tape that is sticky enough to hold down cables for the day, but leaves no evidence when removed. This is important to minimize tripping over extension cords, which can cause personal harm and property loss.
Inspect the room right when you arrive, make sure the tables are as you instructed, pay attention to how the tables are dressed. Make sure there is at least one trash can in the room and that they are easy to spot. At the end of the day return the room to how you found it. Check under every table for trash/cds etc.
Get as much sleep as possible, eat a large breakfast, and bring some snacks (if a meal won't be happening). You won't be taking a break for food.
Name tags are a given, either the cheap sticky ones, or the nice ones with plastic holders and lanyards ($50-75 for a large enough supply). Table 'tags' are something I came up with in 2012, I think, that is basically a folded card stock with the username of the person showing gear and their avatar (helps people connect). I do this for vendors as well, but they usually have their own paraphernalia. This helps people find where they are assigned as well as identifies their setup after they are unloaded.
There are probably other things I'm forgetting, but that is the gist of how to organize and host a larger meet. Once you move into CanJam sized meets you need a staff as it's impossible to organize by yourself.