In my trade guilds, raffles work like this:

The guildmaster posts a list of prizes that players want and that are at least somewhat difficult to obtain (purple/gold racial motifs, gold crafting mats, perfect roe, high-end equipment, a large sum of gold etc.). You will have to have someway to get the items, which can be difficult when starting out. You will personally have to have them or be open to asking for donations from your guildmates.

Tickets are sold to any member who is willing to buy one. Some guilds use a flat rate per ticket (say 1000 gold) and some sell tickets at individual prices for each prize. The ticket fee is either deposited directly into the guild bank or is emailed to the GM.

Before the drawing, each ticket purchased is assigned a number (1,2,3,....54 etc.). This gets more complicated if you allow people to buy more than one ticket, because a single guild member might be assigned multiple numbers.

For the actual "drawing" most guilds use one of the free random number generators found online to select the winning numbers. So if number 16 wins then the guild member assigned number 16 gets the prize. Then you just keep drawing for all the prizes. If you allow members to only win 1 prize per raffle, make sure to choose a RNG that has an option to not select duplicate numbers.

Hope that helps!

I've seen it done both ways in the guilds I'm in. One guild leader would use the member notes to assign the raffle numbers, and I liked that the best b/c I could see exactly what my numbers were. It just seemed more transparent and above board. But I've also seen it work just as nicely with only the GM knowing who had what numbers.

I think the important thing is just making it clear who wins what prizes each week (a list in the Message of the Day area is nice for this), so that people know the prizes are real and someone won them even if they can't be on at the specific raffle time.