Book of integrals

One I was put onto by Paul Nahin in his Inside Interesting Integrals is the two-volume compendium of 1921 by Joseph Edwards, A Treatise on the Integral Calculus, with applications, examples and problems. It's in the public domain and is available as two files via the University of Toronto:

https://archive.org/details/treatiseonintegr01edwauoft

https://archive.org/details/treatiseonintegr02edwauoft

A good book which contains various single-variable integration techniques together with many (and I mean many!) exercises that accompany each technique can be found in chapters 4 and 5 of Problems in Mathematical Analysis by B. Demidovich. It is an English translation of a Russian (Soviet) text. For example, Ostrogradsky's method is given which one rarely if ever finds in English language texts but apparently is pretty standard fair in Russian texts.

There are many PDF worksheets you can find on google that come complete with worked out solutions.

https://www.google.co.il/search?q=integral+pdf+worksheet+answers+pdf&ie=utf-8&oe=utf-8&gws_rd=cr&ei=PC-IVpP7EIPcUaueovgE

Why buy a book when you have the power of the internet? ;)