Can you think of any good threads tutorial/documentation?

[H00G0]

Hello guys!

I'm thinking about picking up threads but I don't really know where to start. Quick google searches give me either two pages on websites or 300+ pages pdfs.
Is it really that complex to pick up the basics, and how would you advise I go about doing so in a few days?

Thanks in advance for all advice.

Regards,

Hugo.