For certain business (General Debates; Second Reading Debates), Members of the House of Lords can sign up for the Speakers List. These are not complied for business in which moving amendments to a Bill are discussed (such as the Committee or Report Stages).
It can be useful to look ahead to see how much interest there is in a debate. Yesterday Lady Thornton tweeted that (by 09-00 on 5th October) 73 Peers had signed up to speak in the Second Reading Debate on the Health & Social Care Bill, which is due on 11th October. An indication of the keen interest in that Bill.
The information can be found on the Government Whips' Office website here.