Welcome.
Do some study first. Local topography.
Do you live in a good wind area? If the answer is no, then building a wind turbine may only be a pleasant engineering interlude.
If Yes, buy a copy of Hugh Piggots book. Many people on this website have started this way including yours truly.
The web site for Hugh is at this URL
http://www.scoraigwind.com/Hugh also lives in the UK - Scoraig Peninsula. He can also supply some items that may be hard to find.
To do a good job you will need access to a lathe, drilling machine, welding, woodworking tools, fibreglass, and of course, patience!
Keep coming back to this website and you will receive much help.
David in Hong Kong (expatriate Brit)
I'll try and put up a photo of my version of Hugh's 2.4 metre (8 foot) 12 Volts DC machine in a few hours time. I went to the trouble to improve Hugh's machine by using stainless steel wherever possible (except for the magnet rotor), a different housing for the AC/DC rectifier, thrust bearings. tail boom lock so that it cannot come off and various other items.