warning spoilers
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I ran all three, and enjoyed them. Here are the things I remember from those sessions.
First, get the next two modules before you start. You really need the info in the third one so that you can lay the groundwork for it while you run the first one. Such little details as the fact that the high priest of the God of knowledge, who is always out of the office in the first module, is only fourth level! A lot of thought needs to go into the setup of the temple of knowledge, as so much of the plot revolves around it. The third module gives you the political setup of the town, and knowing that beforehand helps a lot. There are also a few free downloads that are worth getting from their website. Be warned, If you use the map of the temple there, you need to adjust the attack on the temple as presented in the mods, as they don't quite match up.
Decide what the yellow sign is, what it looks like, and how much the PC's can find out about it. They will see it a lot.
Area 6 of the temple of the unspeakable one has a pool of water. In the later mods the snake people bring a lot of stuff out of that pool as it connects to something else. Decide what that something else is, or make sure the PC's can't go down it. One potion of water breathing can really be embarrassing.

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Decide what language the travel logs are written in.
On a related note

, think up something for the turnips.
In the second module, page 18, the deathtrap. It is a real, oh-my-god deathtrap! Get clear in your head how it looks and operates, and consider changing it. I added 4 rounds to the length of the process, lowered the balance DC's, allowed a magic shield and magic mace to gum up the works for a round each, all on the fly, and still nearly killed the whole party.
Think up something nice to go with being awarded the Order of Drac. I made it being allowed to carry weapons in the Old City.
Thats all the stuff I remember wishing I had done when I ran them. Good luck.