While "The C Programming Language" is certainly a great book and a very good introduction to the C language, it has several drawbacks:
- It is somewhat dated, the 2nd edition (the last one) covers only C89 which is now 20 years old. While C99 (the current Standard) isn't universally supported, there are a number of features from it that are supported by many implementations and exposure to them is useful.
- It isn't comprehensive. It doesn't cover many of the standard library functions in any detail and certain intricacies are not explored in depth.
- The text assumes you are already an experienced programmer and has a very terse style which doesn't work well for everyone.
If you are looking for a more beginner-friendly, comprehensive, or up-to-date book, I would strongly recommend C Programming: A Modern Approach, 2nd Ed. It covers every aspect of the language and the standard library in depth, including C99, and is extremely well-written. While the list price is rather high, it usually isn't difficult to find a copy for around $60 USD.