GURNEY, RAYNER & WILLIAMS (shown here) is an excellent textbook, recommended for all second-year A-Level students regardless of exam board.

Different textbooks cover PM2 in different orders, but broadly the syllabus falls into three unequal parts. The first part (Functions, Series, Binomial Expansions) and final part (Numerical Methods, Vectors in 3D, Proof) contain 'stand-alone' topics that can be covered in any order and at any stage of the school year.  

The middle chunk of the PM2 syllabus - Trigonometry, Differentiation, Integration, Parametrics, Differential Equations - is different. These topics build heavily on PM1 skills, and are hierarchical, i.e. Trig and Differentiation connect to Integration, and all three feed into Differential Equations. I call this large and challenging middle part of the syllabus the MAIN CHAIN. From experience, I've found that mastering the Main Chain is absolutely crucial for students aspiring to a top grade in A-Level Maths!

My approach is as follows: (1) make sure the student is rock-solid on first-year Trig, Differentiation, and Integration; (2) focus on Trig and Differentiation, with the goal of 'be able to prove ANY Identity and be able to differentiate ANY function'; (3) when the student is ready, to tackle Integration method-by-method, including 'method identification', i.e. deciding which method to use for which integral, for those pesky exam questions that don't tell you. 

After this, the remaining parts of Pure Maths can be looked at in any order.

In the first year of A-level, Statistics S1 is rather longer than Mechanics M1. In the second year, this is reversed, with Mechanics M2 being considerably meatier than Statistics S2.

I tackle M2 in two parts. The first part is Resolving Forces, Inclined Planes, and Projectiles: these topics build heavily on M1 and once again the key skills are proficiency with SUVAT equations and thoroughness with Force Diagrams.

The second part of M2 is Moments, Statics of Rigid Bodies, and Applications of Vectors. The last of these relies on Differentiation and Integration skills from both PM1 and PM2 - and as such is often best left to the end of Y13.

Statistics S2 again builds on skills from S1 - particularly on Hypothesis Testing - but otherwise should be quite manageable. The biggest new topic is the Normal Distribution, but once this is done then things usually fall into place fairly quickly.   

Once the main parts of the syllabus have been understood, the student is ready to start practising past papers. When doing papers, it is important to mark your work carefully and to analyse where you have lost marks. The following worked solutions and marksheets can be useful for this.