Company is increasing employee count four fold- what are some 'musts' for evolving IT practices / implementing new policies and/or platforms?

Basically just the topic title- what are some innovating approaches to new systems, policies, employee/customer engagement that a small IT team can think about when a company is expanding like this? What sort of things have you guys implemented that made a big impact to the work force, got you pats on the back, etc.?

Thanks for your time!

Edit: 60 employees going on to around 375