How often do I need to update my linksys firmware and if I update do I need to plug out my modem and router?

My strategy is to only apply updates that resolve security defects that have been discovered in prior firmware versions that are likely to affect me or that add product features I would like to use. The firmware updates will usually be accompanied by a release notes document containing information about the update and the issues it resolves.

The router does not need to be unplugged (plug out?) when applying an update, however if it is in a production environment with a traffic load, it would be prudent to wait until it is idle or near idle. Applying a firmware update carries some risk that the device will be rendered unbootable if the update process goes awry and does not complete successfully.