Details of the payment of expenses to Peers (they receive no salary), can be found on the Parliamentary Website.
Members’ Reimbursement Scheme - General Guide: http://www.publications.parliament.uk/pa/ld200809/ldpeers/ldpeers.pdf
Details of Expenses from 2001
http://www.parliament.uk/about_lords/holallowances/hol_expenses04.cfm
In addition Peers and their staff are required to disclose any interests they have.
The Registers Of Lords’ (and their Staffs’) interests:
http://www.publications.parliament.uk/pa/ld/ldreg.htm