The registration desk, aka the front desk, is the focus of your convention's logistics and communication. It is where you will give membership badges and bags to already-paid members, sell memberships and T-shirts, print name badges, print ad-hoc material such as signage, field questions and requests from general members, store materials such as stationery, deal with Tin Duck and/or Ditmar ballots, etc, etc, etc.
On day one, you will need approximately four people to run the desk. At least one of them must be familiar with the convention (e.g. a committee member or core volunteer) and at least one of them should have participated in a reg desk on day one before. There are two processes in need of an industrial assembly-line approach. These are giving badges and books or bags to members who have already paid, and selling memberships to new members.
Hopefully you have closed membership sign-ups long enough before the convention that all the receipt books from shops have come back, Paypal and EFTPOS membership sales have been similarly cleared, and member names have been transcribed onto badges. If this has not been done, you will have people coming up to the desk saying "I bought a membership three days ago, and I have no evidence of this Now what?". If you think this might happen, you should create a policy for it ahead of time. You should also create policy as to whether or not people need to present ID or a receipt to collect a badge and book/bag. (Standard policy is no -- we just trust people, and this works.)
You should separate badges into 26 piles alphabetically; either by first name or by last name -- it doesn't matter which. Be sure to have a rule for people with just one name, such as Wuffie or Steveg. Place these on the reg desk so that people can smoothly queue to receive badges. You can parallelise this process by, for example, having one person behind the desk serving A-K, and one serving L-Z.
You may wish to pre-punch holes in badges, or let members do it themselves. Ensure that your hole punch can cope with laminated badges.
You will need to supply neck strings or ribbons. You can let members choose their own string, cut their own string length, and tie it onto their badge themselves.
Once members have their badge, they can move on to the point on the desk where they collect their program book, or goodie bag, or whatever it is you're giving them. Ensure that there is clear flow from one station to another, and that people won't have to cut across the queue of other members to get there.
On-the-spot membership sales
Some people will turn up without a membership, and will want to buy one. All of your full-membership sales will happen on the first or second day -- after this you will sell only day memberships. You'll need triplicate receipt books (probably more than one, so you can parallelise sales), the EFTPOS machine, power for the EFTPOS machine, and everything you need to make badges: pre-made blanks, laminator, laser printer, label printer, whatever is applicable to your badge process. Once you have captured a new member's name on the receipt book, you can copy off this to create their badge. Filling out the receipt book will take a couple of minutes per member. Creating a badge will take a couple of minutes per member.
Once members have their badge and string, they can move on to collect their goodies. Again, you should make sure flow is clear.
Additionally, some members who have pre-paid will turn out to be special cases: their badge will be missing or mispelt, and they will need clear flow to the computer where new badges are created.
You'll need at least one PC (usually a laptop). You'll need at least one printer, capable of at least black-and-white A4. You'll need volunteers, and a way to track them. You'll need cash procedures, including a way to deal with end-of-day. (Typically this involves counting cash, and dropping excess into the hotel's safe.) You'll need contact information for key committee members, including the guest liaison and hotel liaison.