As you are the DM I would recommend different kinds of things.
If you use minis I'd get a good battle map or any of the other products that help you run a combat. I've seen colored magnetic pieces that can be used as status indicators: wounded, very wounded, flying, buffed, what ever you want the different colors to indicate. Steel Squire also has some cool DMing aids.
If you're like me and love to run games but have precious little time to develop a home brew then I'd look carefully at the settings. Forgotten Realms is HUGE and has little adventure support. In fact most of the major settings have little adventure support. I would look at Eberron and the quality of adventures coming out of the Xendrik Expeditions. I have no personal experience with the campaign, but it's an option to consider.
I also suggest looking at my personal favorite, Arcanis: World of Shattered Empires. If you are looking for something different enough from standard fantasy based on Western European tropes and think the movie Gladiator was awesome and enjoy the HBO series Rome, than Arcanis is the one for you. There is extensive adventure support through the RPGA (which is free to join) and a well developed world where all is not black or white, but disturbing shades of grey. It is a "Thinking Man's" campaign. Not all conflict is best resolved through combat.
Finally, I think the DMG II is a great investment for any DM. It is especially helpful to new DMs justlearning the ropes. It helps overcome many of the early mistakes many DMs make, learning through trial and error. It can't make you a good DM, it gives you the tool set to be one.
Respectfully,
Edward Kopp: Arcaniac at Large
UKon Games Coordinator