1. How did you have your slack channel set up? (i.e subgroups, build groups, etc)
There's a channel for most every subteam. #business (actually two teams but combined), #communications, #electronics, #engineering (should be mechanical), #game-strategy, #products, and #programming.
There's also #general for announcements and such, #random for off-topic chat, then #executive with student leads and mentors, and then #mentors.
On top of that, we have channels for our regionals (#SMR and #RCR) and one to plan our
Business Summit, #smrbs. Those channels plus #executive and #mentors are locked and specific people only get in.
2. Does your team have any guidelines to follow, such as rules that people have to follow?
Nothing specific, but our team has good etiquette in place and mentors usually keep an eye on things to make sure they don't get out of hand. The school itself has some pretty stringent technology and "digital citizenship" rules so those help too.
3. How big is your team?
We just got a whole influx of rookies who could stay or leave so I couldn't tell you now, but last year we had around 50 people, which includes mentors.
4. How has it worked out so far?
Slack is one of the best things to happen to our team. Period. Makes communication and collaboration so much easier. Integrations are really great and helpful. Being able to, at a regional, go in and tell someone in the stands that we need them at the pit for judges or for robot repair is really great and really powerful. We actually just had an application approved for Slack for Education pricing so I'd guess that later this fall we will pay for Slack to get more integrations, chat history, groups, etc.
5. Anything we should know about Slack before we use it?
Go through all the settings and get it set up just how you want it. Have your members get their notifications set up correctly (mentions, and the channel of the department they are in), have them put their names on their account, have them use pictures of themselves so everyone recognizes each other. Use up your integration limit: get Google Calendar to ding you if you update it, have an RSS feed ding you if FRC updates their blog, have GitHub ding programmers if a new commit is pushed, etc. Integrations make Slack the hub for your team and make it really the best tool for your team.