If you're new to C and basically asking whether the above is a good site for learning from scratch, I would strongly recommend that you'd check out some webinars or massive online open courses on that matter. Lynda and Udemy are some solid examples, although learning languages from online video tutors is quite commonplace in 2015. The benefits mainly stem from the audiovisual components incorporated into teaching, which make long-term retention of critical aspects, more effective. Good luck.