I don't know about books, but there are a few decent free pdf's around that are very helpful. The first one below is good for ES trading. Watch what happens at each of the time points that are described and you will be able to develop your own techniques. The 2nd one is for forex. Use these as a guide, not a gospel.
From my own experience scalping on ES and forex is completely different. I have had to use different techniques on each market (ES is much faster). In any case just keep it very simple. A 10 SMA, quick trigger finger, some experience, and iron-clad discipline will eventually get you profitable. Scalping is a very discretionary world so if you are used to mostly mechanical trading it will be an experience!
Scalping isn't for everyone but if you already have trading experience you will find it very rewarding.
Peter