In general I think its a good idea if you want to have a site with loyal punters but it is a hell of a lot of work at least initially, once it reaches critical mass you can offload a lot of the work to more senior regular readers by appointing them as moderators.
In terms of google I’m not sure how much it helps as I suspect Google doesn’t value Forums as highly as for example well written articles.
As with anything you’ll only really find out by giving it a go.