Is SEO worth it?

sabre307 writes: "Working as an IT Administrator for a small company means that I have to be the swiss army knife of technology, from programming to network administration to web master. Unfortunately, it means that quite often I get thrown into situations that I'm not really well versed in. Recently my boss approached me about Search Engine Optimization. Apparently he has been approached by a company that claims to specialize in this. I've taken a look at the company, and I'm not very impressed by them, but it has opened the door and now my boss wants me to do something to bring up our page ranking in search engines. I figured that the collective brains of /. could offer up some advice on how to handle it. First, do you have any ideas on things that could be done easily internally to improve our ranking? Second, are SEO companies worth the expense? Third, if they are worth the expense, how do you tell the wheat from the chaff or does anyone have any recommendations?"