Here is an excellent resource (at least last time I checked and it has been awhile, they used to be called macosxlabs.org). http://www.macenterprise.org/ As far as tools, the built in tools are very good. A third party tool that can be very useful for bootable drive images is Carbon Copy Cloner. When you say large, do you mean hundreds or thousands, or less? It will definitely change things for you. I think that you will be surprised by both the ease of the transition, and the things that should be easy that are not. Really I don't know how we can help you unless you have specific areas where you are interested in learning solutions (and I don't say that to be a jerk, I'll try to answer questions where I can). How many servers? Directory Server? File Sharing? Exchange Server/POP/IMAP? Calendaring? Centralized home directories? Budget per user? Of course there are cool things that cost money and are not really needed, and hard things that are cheap but work well once set up etc. I would help more, but I don't know where to start... take a look at the link above, and ask questions as you get a better idea of he scope

I find posts on using Solar power interesting. If only because I grew up about 21 miles from the nearest town and power lines were not available. It is amazing how people's lives adjust. There are a lot of ways to save energy that are not even thought of in a normal home. Solar water heaters (need to be drained in the winter), wood stoves etc. that are all just part of life in some parts of the country. We needed to use a generator in the winter months about twice a month to charge our battery back. Now most folks are using the grid as a battery bank and just selling power back to the utility when they have extra. I think the problem with this method is that people are not forced to cut back and don't realize how easy some cut backs can be. In any case it is interesting.