Design analoge filters

If you really want to dig-down, the Handbook Of Filter Synthesis (Zverev) is very good.

If you just want to design & build filters, Google "Elsie"; it's a simple design program and the free version is suitable for most applications.

If you are referring to active filters here are some authors I really can recommend:
*Natarajan
* Huelsman
* Deliyannis
* Ghausi and Laker
* Lindquist