I think Protein Engineering: Tools and Applications (editor Huimin Zhao) is an okay intro, but you won't learn protein engineering from books... There are hundreds of publications in the field every month. Just dig in and when you don't understand something, dig deeper.

I am of the same opinion as Madam Radziwon. However, here is another reference: "Advances in Enzyme Catalysis and Technologies" Pandey et al; Ed Elsevier.

I can't find a single book that covers all the useful methods protein engineering. But protein engineering is just plasmid engineering of a gene in the multiple cloning site plus extra steps.

Main techniques are these:

* Site directed mutagenesis. Partial overlapping primers are better than QuikChange.

* phosphorylation and ligation of inverse PCR products to make deletions and insertions in plasmids.

* Restriction cloning and ligation of PCR products into vectors to insert a gene into the multiple cloning site of a plasmid.

* Sequence and Ligation Independent cloning (SLIC) more efficient than the previous method but somehow less popular.

* Gibson Assembly

* Polymerase Incomplete Primer Extension (PIPE) cloning.

* TA cloning. Expensive but easy but also bidirectional cloning which is a problem if you don't know what it means.

* Topoisomerase based (TOPO) cloning. Efficient but only use this technique if you are rich because it is super expensive when other cheaper methods do the same thing.