Two words: Mark Minervini. He isn’t a day trader and I wouldn’t use FT for day trading, but across a longer time frame and using other tools that provide volumes data (eg Koyfin, which is free) Mark’s book provides some really useful ideas on trading within a short-medium time frame.
I found his book after one of the FT board recommended the book 100 Baggers on an AMA in the summer (also an interesting read!).