Since 1993 a decision of the House of Lords decision has allowed, in certain circumstances, that the statements made in Parliament by Ministers or other promoters of the Bill can be resorted to to help determine the meaning of the subsequent act.
This is often referred to as the rule of Pepper v Hart.
If you are engaging in Pepper v Hart research there are two subscription databases which will help. (For both remote access requires Oxford SSO.)
Alternatively, on the Ground Floor of the Law Library is the Bodleian Official Papers collection where you can find Lords & Commons papers, Committee reports, and volumes of Hansard in print format.
Some subsequent UKSC cases considering statutory interpretation
Public speeches on topic from Supreme Court Justices
Chapters in introductory works on learning English law will naturally include a chapter or more on this. They can be useful first steps. Older/traditional works will probably consider three rules: the Literal, the Golden and the Mischief. In a decision of 1992, Pepper v Hart [1993] AC 593 initiated new avenues to attempt to determine the meaning of certain legislation when it is ambiguous or obscure .
But naturally there are books looking at this issue in detail - from academic to practitioners to philosophical analysis. Some examples are below
Bennion on statutory interpretation by 
Craies on legislation : a practitioners' guide to the nature, process, effect and interpretation of legislation by 
Thinking about Statutes : Interpretation, Interaction, Improvement by 
The Nature of Legislative Intent by Some views on statutory interpretaion from the USA
Dynamic Statutory Interpretation by 
Purposive interpretation in law by Passage of Bills
Quick links to stages for example Second Readings "the first opportunity for MPs to debate the general principles and themes of the Bill."
For help with finding & using Hansard (online or in print on the Ground Floor) and other government official papers, please start with the special guide below, created by a Bodleian Official Papers colleague
The Law and Parliament by Explanatory Notes to Westminster acts were introduced in 1999. Note: "certain financial Acts do not usually have Explanatory Notes, including Appropriation Acts and Consolidated Fund Acts. Acts that have been introduced to Parliament by the House of Lords often do not have accompanying Explanatory Notes" https://www.legislation.gov.uk/help#
Explanatory Notes will be a clickable link on the result page between the title of the act and the text of the act on Legislation.gov.uk
Explanatory Notes to bills can be found among the 'Bill documents' on the relevant Bill page
