I don't think there are any tutorials out there on this. What kind of stuff do you plan to do? I have done a little work with some weather and all I can suggest is looking at the wiki http://geck.gamesas.com/index.php/Weather for it and figuring out what you need. Also look at the page for Climate. If you want to simply add a custom weather/climate type to your worldspace or cell then you can do it by yourself with the wiki pretty easily. If your looking to make more of a complete weather overhaul that adds entirely new weathers everywhere, then its mostly stuff you can do alone, though perhaps we can help you with some of the scripting. What do you plan to do?
I need to redo the entire weather system for Fallout 3 for my http://www.fallout3nexus.com/downloads/file.php?id=11459.
Here is the following weathers I am trying to make
Current Weathers I would Like to add
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Clear Sky - No clouds just the sun beating down on you.
Small Sand Storms - Small where you can still see pretty clearly, just not completely
Large Sand Storms - Can Barely see anything in-front of you.
Day Sky - What it looks like now.
Other Addons
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An esp that will give the player nagiatives for being in certain weather like Large Sand Storms and in Clear Sky (Reasoning, Large Sand Strom you wont be able to see anything and Clear Sky the sun will be beating down on you so you will be over heated.
ESP to add rain from the Enhance Rain mod - Because even a desert can experience a little rain every now and then.
Any Help you can offer would be great.