distributions and delta function

[jadoo.dost]

where can I read about distributions and the delta function. esp. to solve singular integrals.
I have seen that you could write

1/x = \delta (x) + P.V (1/x)

and all that stuff.. where can i read about it ....

[Anthony]

I found Friedlander's book (http://www.amazon.com/Introduction-Theory-Distributions-F-Friedlander/dp/0521649714) very good, with a nice insert at the end from Mark Joshi on the calculus of wavefront sets. :)