Once the list is closed - it is arranged into order - after consultation "through the usual channels" (defined as the Leaders and/or the Chief Whips of the three main parties, and sometimes (but not always) the Convenor of the Crossbench Peers - Handbook of House of Lords Procedure - Mary Robertson and Thomas Elias (Dods: London, 2006)).
The final list usually appears at around 2pm on most days.
Anyone can see the lists at http://www.lordswhips.org.uk/display/templatedisplay3.asp?sectionid=5