Here's a fairly readible paper on a nearby cloud that is collapsing. The cloud is about 500 light-years away, and all told has a mass of about 80 solar masses, but this dark cloud is relatively extended, and will probably form several stars. One collapsing area in particular is studied in this paper which seems to have about 2 solar masses in it.
A Pre-Protostellar Core in L1551
The paper points out that we do not yet know that much about the magnetic field inside this region, and that this will certainly factor into how long it takes this thing to collapse, and how it does it.
It will be interesting to watch this and other similar regions in the dacades ahead. As the collapse should take roughly 300,000 years, instruments like the SKA should be able to observe real-time progress towards collapse in as little as ten or twenty years.
Forming opinions as we speak