For books, tutorials and more that will help you understand evolution, please visit this tip sheet: Learning about Evolution.
Research tips:
Closely related species (like those in the same genus or family) will share much of the same evolutionary history. So, when looking for information about a species' evolution, you may need to step back and look at larger taxa.
As an example, consider the Eastern Tiger Swallowtail. To learn about its evolution, I would start by searching for it by species. If that did not bring me enough results, I would move down the family tree, searching for genus, family and order in turn:
1. Papilio glaucus AND evolution
2. Papilio AND evolution
3. Papilionidae AND evolution
4. Lepidoptera AND evolution
Articles and books dealing with the evolution of the genus, family and order are likely to discuss at least some of the individual species within those taxa.
Also try substituting the words "phylogeny" or "phylogenetic" for "evolution" (i.e. search for Papilio AND phylogeny). Phylogenetics is the study of evolutionary relationships, so searching for words related to it will bring you good results, too.
Not sure where to start searching? Try the library's "everything" search. It searches most of the library's databases at once, making it a good one-stop shop for articles and books. Click here to see how it works.