The biggest issue you have is that a) the extent to which the work of Pocock/Skinner/Dunn etc. is cohesive enough in approach (or even intended to be so!) to be counted as a school is debatable b) the extent to which they have remained consistent to the manifesto exploded onto the scene back in its inception is even more doubtful. So you are engaging with something a little shapeless (and arguably intellectually provincially-bound), thus the works are limited and can be tentative. In addition while it is not necessarily defunct there is something a little dated about it, at least at the pointy end of articulated discussion (although not necessarily within the practice/craft of those who dont't write methodology/theory of history works).
I would start with Tully's work (Meaning and Context: Quentin Skinner and his Critics), it has the original manifesto, a well put (if sympathetic) outline by the editor and critiques and responses (although while they were (broadly) representative of the era of publication many of the lines of attack are somewhat dated. As someone certainly not hostile to the ideas coming from Cambridge at the time it does at moments feel like a kindly-selected set of essays. Nonetheless it is very helpful to root the ideas, as I have found some more hostile characterisations a little bit caricature-y at times.
From there the best bet (and it depends what you are looking for/level you are looking at) is either:
A) Look at general survey works on intellectual history which will therefore generally have a section on the Cambridge School. Some examples of ones with sections (literally off my bookshelf, there may be other ones which others can suggest)
- What is Intellectual History - Whatmore
- There is also an interesting chapter in 'A Companion to Intellectual History' eds Young and Whatmore
B) Essays specifically about it, normally 'partisan' to a degree and can get very theoretical which can be difficult to jump in on without a broader primer as to the debates they are situated in. For example:
- Bevir's 'The role of contexts in understanding and explanation', although I would say that despite the fact that Bevir is (for my money) very good, his stuff on Skinner does always feel a little "doth protest too much". So take the distinctions he seems to draw between himself and Skinner with a pinch of salt.
- 'Quentin Skinner's revised historical contextualism: A critique'
- 'J.G.A. Pocock and the idea of the ‘Cambridge School’ in the history of political thought'
- 'Quentin Skinner, the Cambridge School, and Contextualism'
- 'Intentions and conventions: a critique of Quentin Skinner’s method for the study of the History of Ideas'
- 'Quentin Skinner's rhetoric of conceptual change'
There are many many more, so I would search around yourself - i literally just opened up my Mendeley and listed a few I remember being interesting back when I read them - this is by no means a representative sample, particularly lacking is the linguistic turn critiques on this list. I make no further comment.
Best wishes with this - it is a fascinating area!