"Bookstore" CC BY-NC Randall Munroe
...and it's actually also nearly impossible to infringe something just by talking about it.
What copyright owners own is the right to decide who (if anyone) gets to make/distribute copies of a work, who gets to produce derivative works (like translations and adaptations), and who gets to perform or display the work publicly. (17 U.S.C. § 106)
Talking about a work rarely involves any of the activities that copyright owners are allowed to control. You can name the work (titles are not copyrightable in the U.S.), summarize the work in your own words, and criticize the work without even raising a copyright issue.
Somehow this continues to be an issue people worry about with respect to links online - I still fairly regularly field questions from people who have been told that linking to a publicly available web resource requires permission. But fundamentally, all that links do is tell people where to get a legitimate copy of a work - they're just another form of talking about the work. Can you imagine if copyright law prevented you from telling friends about a great new book you just got from the library?
Of course, with all things copyright, it's never quite that simple. Linking to illegal or blatantly-infringing content is generally held to be a problem, especially when the intent of the link is to encourage illegal activities or infringement. Linking can raise trademark issues, especially if there is intentional or actual (even if unintended) confusion about sponsorship or endorsement of a site or of content. It can be difficult to pick apart and apply the court rulings, especially since judges that do not understand the technological realities sometimes issue opinions that are difficult to apply in the real world.
Learn more about legality and links from Chilling Effects/EFF and Links & Law.