I have taken an introduction course online in descriptive statistics and probability last year which used R from the start and now I am taking an inferential statistics class.
I find that I need to find other sources of information about statistics.

What materials and resources would you recommend to a beginning adult self-learner?

For example, http://www.biostat.wisc.edu/~kbroman/Rintro/ posits:
The most important book:
WN Venables and BD Ripley (2002) Modern applied statistics with S, 4th edition. Springer

Would it make sense to concentrate on Venables' text if my goal is to learn statistics?

Modern Applied Statistics with S is an excellent book. So is Data Analysis and Graphics Using R, by Maindonald and Braun. If you are just starting out in the area of statistics, these books are likely to prove challenging.

If you are looking for some good on-line courses, you might want to look at offerings from Statistics.com.
I have taken a number of courses from them, and most have been good.