There are so many phenomenal sewing resources on the web.
If you have a question there is probably a youtube video, blog post or web page on the topic.
Use your search engine to do some research and bookmark what you might use again in the future.
I also encourage you (if you haven't caught on already) to find bloggers who post on topics you are interested in, bookmark and/or follow them as well. I've found so much inspiration and education on blogs and websites of other sewists and pattern makers.
It helps when the artist has an aesthetic that you can appreciate. Personally, in particular, I am drawn to blogs with light filled photographs, clean and easy navigation, with clear and add free posts and modest information in accessible organizations. Find and discover your own attractions.
Many pattern makers and bloggers host tutorials on topics of sewing that can be used as references when sewing their patterns. Others simply offer tutorials and information on any subject that interests them or that they imagine others might find interest in. I have chosen not to try to duplicate what's already out there, and only to offer either information that I think could use improvement or information that supports my patterns and tutorials.
If you don't want your own library of books I encourage you to see if your library has an "interlibrary loan" program. I live in California and can borrow books from libraries across the state and sometimes I've even found libraries outside the state to participate. If you are a lover of reference and the wealth of knowledge and learning books can offer, I encourage you to borrow books first to see if they suit you and if they do and you want more permanent access you can purchase them to own and if not you didn't waste a penny on something you don't need!