Since I didn't know a Boer from a boar when I started this period here is a list of books I have found helpful. When I start a period I like to follow similar research techniques. First, Uniform help then a broad overview no more than 150 pages just to get a feel for the period. A indepth work is next then books about individual's or individual units.
Uniform help Osprey makes several books. I have found the most useful Ian Knights volume 2 Of his Boer war books. Good plates and text divided between campaign history and equipment/ tactics. highly recommended 4/5 stars. Other osprey books I have found helpful are the Australian and Canadian books. there are several other titles that look interesting but I do not have.
My overview book was Micheal Barthrop Slogging over Africa the Boer wars 1815-1902. Tons of good pictures and a lively text made this a quick read. The part on the 2nd war was around 100 pages, my only quibble was a lack of good maps,recommended 3.5/5 stars.
On a More involved note I am halfway through Thomas Pakenham's the Boer war. At 613 pages there is more than enough detail for everyone. Good background information and plenty of good battle information and maps make this a long but worthwhile reading 5/5 stars.