Because many of the software programs are open source, a lot of the documentation and literature surrounding them are also freely available. Places to consider searching are the websites of the respective program/software/language etc, blogs from the creators, user groups and other associated sites/programs (for example exploring GitHub with respect to Bootstrap). These resources will focus on the practical application of the software whereas more theoretical content (as well as practical) will be found in journal literature.
These books can be helpful for the practical applications they provide but also check out the first chapter or few paragraphs as they usually contain some history regarding the origin of the subject.
If you come across material you would like but Siena doesn't have, it may be able to be requested through Interlibrary Loan.