I was originally elected at the local caucus level. After I was elected I had to submit some paperwork to the KSDP to signal my intent to run as a delegate at the regional/Congressional District. Then I had to go to the regional convention for the 3rd Congressional District and I was elected as delegate directly to the DNC. fwiw, I was competing as delegate with another DU'er. We were divided up according to whom we were representing. The Kery delegates got to use the auditorium. The rest of us were informed that the local caucuses had yielded enough delegates that one non-Kerry delegate would be elected from our group. I was elected as a Dean delegate and I represented the Kucinch, Dean, Edwards and Clark faction of the Kansas party.
My alternate was choosen by a vote the next month at the state convention. There were also a few at-large delegate positions available that went to people who ran for those positions. Like me, these alternateds and at-large positions required you to fill out some paperwork and submit it to the state party.
After I was elected I was contacted by the state party and given instructions on how to sign-up for the DNC's delegate registration. I got an e-mail with instructions on how to reserve my room (the states had been assigned hotels) and other information. Both my husband and I had to pay our own transportation and hotel costs.
In the weeks before the convention itself, I was flooded with both phone calls and e-mails, from seemingly everywhere. I was interviewed and polled by numerous national news organizations (ABC, CBS, MS/NBC, CNN, Boston Globe, New York Times, etc.). One of our jobs was to contact local media and do interviews. Otherwise, our job was to keep and create a buzz (get people excited) on the local level about the upcoming convention.
As a delegate it was an interesting experience. The days are pretty much free to attend classes, caucuses or go sightseeing. My husband and I attended seminars and clssses by the likes of David Brock and Roberty Kennedy, Jr. We also attended and participated in the Native American caucus. Then we found the progressive convention across town and started going there. We saw Dean, Kucinch, Conyers, Bill Moyers (of the Backbone Campaign) and Medea Benjamin speak there. Below is a picture of Dean and Kucinich at the progressive convention.
In the early evening they would send the busses to take us to the convention center. You could only ride the bus if you had a delegate or alternate badge, so my husband and I took the subway several times to get to the convention center so we could go together. The Kansas delegation stayed in the same hotel as Tennessee, Utah and one of the Dakotas.
My advice would be try to go as a delegate. It is a lot more fun. You have more free time to go where you want. As a volunteer you're stuck wherever they ask you to go and do whatever they want you to do.