What advice are you exactly looking for?
Just general advice on GM'ing a game?
I had never GM'd before, and had never played FATE or DFRPG, when I started GM'ing my weekly games for some friends. We broke one year of playing back in January and are still going strong. None of them were familiar with the FATE system and only 2 of the 5 had read the books at the time (now 3/5). I found the game mechanics and system itself (other than magic) to be extremely simple and flexible in all the right ways. Keep in mind this is a storytelling system, at least in my eyes, and it lends itself to sessions built as such. I worry a lot less about intricate maps and such and a lot more on characterization and PC/NPC/World interaction. The biggest piece of advice I could give to anyone who's going to GM a FATE based game is do not plan too much. The system is all about PC choice. They can do a LOT between ritual magic, declarations, and the like. What I do is make the NPC's, the locations, the plot hooks, and design scenes in a "What do I want this scene to accomplish?" kind of way. If you try planning too much of a "railroad system" you'll find it going south really quick. Have a mansion the players need to break into? For the Burglary part stop there. Let them figure it out. Don't design some special security system, because undoubtedly a Wizard will hex it. A super cool lock system? A PC will scale a wall and go in through a less secure window.
Base your scenes, sessions, and entire campaigns on "skeleton ideas". What you want to accomplish and how you want the story to develop and then let that magically happen during your game nights. It might require you to think fast sometimes, but it'll be worth it.
Hopefully this helps, but if you have more specific questions let me know. :-)