When it comes to architecture it always depends. When building a simple throw away application you document way less than when building a large service oriented architecture. When building an application in an agile organisation you document less then when building an application in a highly governed waterfall organisation.
When it comes to determining what to use I like the IEEE 1471 way of thinking
(image from http://iea.wikidot.com/ieee1471 )
Look at your stakeholders, determine their concerns, identify the viewpoints which best describe how your architecture addresses the concerns, describe these viewpoints.
As an alternative and a more common way the "4+1 Architectural View Model" addresses the need for a lot of projects.
What you probably did not mean, but which could give you also some new ways of thinking about it is the PSA (Project start architecture). Which is more of an enterprise architecture document. A great presentation on the PSA and how it fits into TOGAF can be found here (pdf)
A great book that also give a lot of insights on how to describe software architectures is "Software Architecture in practice" ( third edition coming out soon)
Hope this helps and good luck.