Hashing algorithms won't help you optimize your data retrieval speeds.
They simply calculate a checksum value for the string you pass it. The checksum value is either a 32 char (MD5) or a 40 char (SHA1) string that can not (theoretically) be *decrypted* into it's original value.
As such, they are mostly used to permanently *encrypt* data, such as passwords, into the database.
And seeing as the hash is irreversible, it will not be of any help when retrieving data.
I don't really read books, so I'm sorry to say I can't help there. The
MySQL reference manual is very helpful tho.