The pkgsrcCon 2013 was my first developer conference. I've been to other conferences before, but they were rather large and not strictly about a single topic.
There were some things I learned from organising the pkgsrcCon I didn't expect to be that way:
In the beginning, I thought, the conference would just be announcing the event, and the rest would happen by itself. But it's much more effort needed…
You have to organise people holding talks, do advocacy (think about other projects, find according lists), answer requests from participants, update the website, settle the schedule, find a place for the events around (dinners and social events, maybe hackathon).
Don't think that you'll only do something around the event (apart from the organisation). If you have the event on Saturday, take the whole Friday, Saturday and Sunday. On Friday, you have to take people out for dinner. On Saturday, the event itself is going on, and you have to prepare it onsite and clean up afterwards, then go to a social event. On Sunday, many people are still there and want to do a small hacking or chillout session, so the whole day will be required again.
I did the mistake to plan for a social event that was not possible in the end. So there was no real social event, only a small group of participants going to a bar, having food and then some drinks. I'm sorry for all the pkgsrcCon participants who expected more!
Optimally, you reserved a table in a restaurant for that evening, have a bar handy for the social event, and everything within walking distance of the event site.
I heard several people saying they preferred the location (IN-Berlin space) over the usual university setup. In a typical hacker space, you have a small and cheap coffee bar, fridge, and maybe a kitchen at hand. You don't have to care thaat much for opening times of the university, and all the people are crammed together - there are no large walking distances from one room to another, and it's more family-like.
When the participants prefer to have a hacking session after the conference, they can just stay there, or even have the social event/chillout in the hacker space itself - provided there is some beer and Mate available.
I thought: No problem. I will record audio by mobile phone, and video by camera.
Indeed, this worked (for the conference). The microphones of mobile phones are useful, so if you strap them around the neck of the speaker, switch a recorder on (I used urecord for Android), then you'll get decent audio recordings.
For video, the same holds. Just remember to have a camera with an external power supply and an unlimited or at least reasonable maximal record length (not 15 minutes).
But then, there's another problem: A small developer meeting is more like a discussion than a conference with a speaker and the audience. There will be many comments, discussion inside the talks, live presentations (you would need a screengrabber for that), making recordings more difficult.
So expect to buy a conference microphone (which is rather expensive) and a good camera with a tripod you can sway without hassle if you really want to record everything. Even a screen grabber could be necessary, as there are many presentations, and you can't capture everything with a camera.
This holds for all conferences: Start right in the beginning to collect slides. Ask the speakers to give them to you maybe even before the talk. It will save you much stress during and after the conference about collecting the slides to bring them online.