Praveen bhai ney jyaada tar queries reply kar hi di hain, few things I want to add.
1. How much minimum investment is needed
If starting with FNO, ideally you should have few lacs.
You can trade intraday nifty futures with 15-30K, and options with even less than 5K. But if just starting, initial losses might be unbearable. Also how would you put 2% stop loss of nifty futures when trading with 20K?. You will give only 5-6 points room to nifty to move against you. Too many whipsaws will occur and even slight slippage will increase your percentage loss greatly.
2. are there some books,courses available ?
Search torrent sites (esp. the one with name similar to yours....
, itni books mil jayengi ki padhtey padhtey aadmi swarg (on narak depending on his deeds.
) sidhaar jaayey. They were there in megapacks of few GB. Lots and lots of books. Same with videos, many of them, not much on torrents (esp. since demenoid shut down), but can find them on file hosting sites.
3. Also is there demo trading available with fully T.A(charts) where I can practice ?
You may open account with any of the bkgs here and use there terminal.
Demo Trading: Available on Omneysys Nest site (NEST plugin waley), which you get with NSE NOW terminal.
Good Charting and TA - Sharekhan Tradetiger but bit high brokerage.
NSE NOW - Okish charting with NEST plugin, accurate quotes, very fast trade executions. You may open an a/c with any of bkg that provides NSE NOW or go for tradetiger.