From 35C3 Wiki
The congress is an event with a rather decentralized structure and as such can be a little overwhelming for first-time attendees. This page was made to let you know what to expect, how to prepare and hopefully enjoy the event enough to make you want to come back the next year.
What to bring
Not much to say here, only that you should check the inofficial CongressChecklist and that when bringing any personal belongings, it's also wise to read the page that explains how to keep your items and information safe.
Upon arrival at Leipzig main train station, you can travel to the fairgrounds quite easily.
Once you reach them, enter the big glass hall that you'll see after you pass by the lake. There, you'll need to show your ticket and will receive a wrist band that you need to wear throughout the congress. Once you take it off, it becomes invalid. Hence, it's a good idea to not make it too tight or else it may be uncomfortable to sleep with. When you have the wrist band, you can come and go anytime - even at night. Tram 16 is also going to run all day and night, so you don't need to worry about being stranded at the fairgrounds.
Don't be surprised to find the main areas to be very dark even at day time. It allows us to decorate everything in blinking lights :) If you need daylight, the glass hall in the middle of the fairgrounds allow you to synchronize your inner clock - short of leaving the congress and venturing out into the cold December air.
What to do at the congress
Of those, all official talks and lightning talks are recorded and will be available for watching after the congress. This means that at the congress, you can relax and attend side events without having to fear missing out on the talks. Of course, if a specific talk is of particular interest to you, you would like to take part in the Q&A session or you would like to get in touch with the speaker, you should definitely attend.
So which side events are there then, you ask? Frankly, it's difficult to provide a complete overview. There are lots of groups and individuals offering lectures, trainings, workshops and other events such as food tastings and not all of them announce them on the self-organized sessions page. It's best you take some time on your first day to just walk around and keep an open eye for posted schedules near rooms in the congress center or the stages that you encounter.
Assemblies (groups of people with a shared interest) sometimes also offer hands-on workshops or trainings, either at the location of their assembly or in one of the rooms in the congress center. The easiest way to find out about those is to look for assemblies that interest you on the assemblies page and check their page to see if they have posted any events there. If they haven't, don't feel shy to contact them and just ask - your inquiry may be the reason a workshop or training will be offered!
Aside from all the official and inofficial events, it's a good idea to just walk around the fairgrounds and have a look at what people do. It's quite likely that you'll find people who are interested in the same things as you are. As a lot of us are nerds, it's likely that we'll be sitting in front of our computers, hacking away. However, you shouldn't let that stop you from approaching anyone who does something that you're curious about. Ask questions, get in touch!
Also, don't forget that the congress is diverse. You will find groups that discuss environmental issues, groups that discuss social issues, groups that hack on hardware, groups that hack on software, groups that develop open source software and lots more. Keep an open mind and you'll be able to learn from a lot of great people.
Congress at day time
Usually, the congress fills up slowly in the morning and it's not until noon that you'll see the congress in full attendance. Thus, if you prefer the quiet and would like to avoid crowds when visiting assemblies, mornings are awesome.
When you're hungry, there are unfortunately not too many options at the congress itself, especially if you have special dietary needs. While there are some food stalls that serve food of varying quality, it's best to check for options ahead of time.
Congress at night time
After 6pm is when you'll find that attendance is highest and noise levels are highest as well. While some may be trying to get actual work done, it seems to be the time when most people hang out, socialize and party. You might want to do the same :)
This is especially true after midnight because that's when it's allowed to play loud music. Trying to get any work done in the main hall and the congress centre becomes virtually impossible at this point.
The on-site food stalls close sometime in the evening, so if you intend to stay until midnight or longer, you might want to make sure that you ate before there's no more food available.
There's a central help desk that you can always consult in case you have questions or issues of any kind, so you don't need to worry about feeling helpless. Also, virtually any congress attendee will try to be helpful if you ask nicely. We try to be one big community.
Finding the locations of the talks, assemblies and workshops can be a little hard sometimes. For this reason, it's a good idea to use the c3nav system that provides a meaningful map of the congress.