You can sit there and read it for free, or you can pick up a copy to take home for only L$100.
It explains everything that I think you should know before you start to make clothing in SL.
I start by explaining the difference between texture clothing and prim clothing. Then I explain how to make clothes using the Appearance dialog, in case you don't know that.
Next, I explain what a 3D mesh, such as the one that makes all our Avatars, really is, and what a UV Map is. I talk about the 3 UV Maps that are used on our avatars, and why we only have one arm, and one foot, for texturing purposes.
After that, I discuss Clothing Layers - what goes on top of which, and how much of the AV each covers.
Then we get into the meat of the topic, as I explain how to wear a "UV Suit" (which is included in the book, using a Notecard) to design clothing. How to test for errors before you've put much work into a garment, how to get onto the Beta (Preview) Grid, so you can save Lindens as you test your work, and how to fix things when you find glitches.
Finally I show you the common problem areas on the Avatar - things that always stretch, and how to deal with them.
As a bonus, at the end, I talk about how to use repeating patterns as fabric for your clothing, by making Patterns in Photoshop®.
All of this is presented in a 42 page THiNC book, fully illustrated, with a link to my Website (so you can get the Subdivided UV "Templates" to use in your own work) a Notecard full of textures and UV/Test clothing, and landmarks to the Texture Tutorial and Texture Library where you can find other books. (Assuming you're not sitting there reading this one.)
If you're not familiar with THiNC books, they are as close to real books as I've seen in SL, with turning pages and everything. You can read them by zooming in, or, if you own the book, you can wear it as an HUD. I think it's the perfect way to publish a reference book for you to use in SL.
But come see for yourself! You'll find the book at the Texture Library on Livingtree.
See you there!