Setting up a CRM for a 12-person team, where do you even start?

Choose the tool partly by what your email and calendar run on. If everyone lives in Gmail or Outlook, check the add-in for that is properly good. If logging an email takes more than one click, nobody will do it and the CRM goes stale in a month.

Not in the CRM. Start on a whiteboard. Write down the stages a deal actually goes through at your company today, from first contact to paid, and what has to be true to move from one stage to the next. Five to seven stages is plenty. Then list the handful of fields you genuinely need on every contact and deal. Everything else is optional. Then pick a tool, set up only that, and import a cleaned list (dedupe first, it's much harder after). The setups I've seen fail all had 40 required fields on day one and nobody filled them in. Give one person ownership of the CRM so field changes don't happen by committee, and expect to tweak the stages after a month of real use.