Inara Pey posted an interesting guide on the new feature that will rock Second Life: mesh import. I recommend you read her post for an introduction on the what, why and how to use mesh.
Read about the issue of scale in Second Life and how you can position your viewer cam from this post by Natales Urriah.
An excellent 4-part tutorial by Anya Ohmai on how to tame your inventory. Click the link to visit her blog.
If you want to learn how to sail in Second Life, or improve yur skills, you must read this tutorial by Orca Flotta. Click the link to visit her blog.