You've hit on one of the hardest things!
I have to admit that I don't feel communicating in a timely fashion is my forte. Not only because I don't have as much time as I would like but also because it's too easy to get completely immersed in the finer details of the project and to forget to come back up for air and to communicate with others.
Having said that I tend to communicate by having meetings with the project team, adding a few lines to our management team briefing notes on progress (these then get passed on to other teams in the library) and occasionally by sharing some news on our Intranet.
Annual restrospective cataloguing figures are published in our annual report, which is available on our website and in hard copy for those of our members who request it (we're an independent membership library). The list of sections completed and being worked
is also available to staff via our intranet and to members (and anyone else) on our website.