I know this is ComputerWorld, one of the ad-driven free mags that tend to review products and state the obvious, but this quick article on 10 tips to secure VPNs is a pretty good and quick read with some specific technical details as well as common sense items that are sometimes hard to get management levels to listen to (such as only opening the VPN to those who truly need it). I like that some of the points are actually alternatives, such as secured mail or SSL/passworded web sites when, really, the need is smaller than the justification for a full VPN solution. Unfortunately, in other instances like jailing users from the rest of the network are a bit more advanced and complicated.

Of note, this response was given on Infosec News and deserves to be read in conjunction with the original article as the author makes some excellent points.