I suggest Gelbart Lecture notes Arthur trace formula in addition to Gelbart Jacquet (Aakumadula`s r eference).

Deitmar Echterhoff Principles of Harmonic analysis is good for a conceptual approach (cocompact case only though). No detail ommitted.

There is also a long set of notes by Arthur and a LMN by Shokranian.

I suggest Gelbart Lecture notes Arthur trace formula in addition to Gelbart Jacquet (Aakumadula`s reference).

Here is a site with references: http://www.charlesli.org/math/trace.html

I suggest Gelbart Lecture notes Arthur trace formula in addition to Gelbart Jacquet (Aakumadula`s r eference). Also Deitmar Echterhoff Principles of Harmonic analysis got me going (cocompact case only).

There is also a long set of notes by Arthur and a LMN by Sholokdrian.

I suggest Gelbart Lecture notes Arthur trace formula in addition to Gelbart Jacquet (Aakumadula`s r eference). 

Deitmar Echterhoff Principles of Harmonic analysis is good for a conceptual approach (cocompact case only though). No detail ommitted.

There is also a long set of notes by Arthur and a LMN by Shokranian.