Shopping for Building Access Security?

JoeCommodore asks: "At work we are planning a new facility, which will combine a lot of departments into one bigger building. We think it may be time to forgo analog key access and go with access cards (or something like it) for physical security. I could see the benefits (we don't have to collect keys and re-do locks on staff turnover, selective room access, access logs, and so forth). Beyond this, we are pretty clueless on the ins and outs of such systems, so I am asking those of you who have had to shop, install, administer, or even just regularly use such systems, what are your thoughts, recommendations, or opinions? This is pre-building so we can do just about anything within reason."