As a biologist who started to learn R, I encountered a lot of problems on learning the subject. Now I don't want to go into them but I just want to suggest what I think that can save you from wasting your time and energy fooling around without getting what you expect.
- Install R ! Of course!
- Install R-studio, this simplifies your life. Note: R-studio should be installed after R. (http://www.rstudio.com). After this you always open R-studio not R. R is the actual program but R-studio gives it the nice interactive interface.
- Watch this webinar on R to get familiar with basics and why it's good to have R-studio. http://bitesizebio.com/webinar/20600/beginners-introduction-to-r-statistical-software/
- Coursera offers this very nice course in R. Get the videos from their website and of course watch them! (https://www.coursera.org/course/rprog)
- While learning from the course, practice with swirl ( http://www.swirlstats.com ). Swirl was the best R teacher for me. It interactively makes you work around with R.
- Also https://www.datacamp.com/courses/introduction-to-r or generally https://www.datacamp.com is very good resource for self learners!
- Stuar51XT is a youtube channel that has very nice comprehensive R courses. Just in their videos search for "introduction to R programming" https://www.youtube.com/user/Stuar51XT .
- Practice and expand bioinformatics oriented R skills by "Institute for Integrative Genome Biology" manual. http://manuals.bioinformatics.ucr.edu/home/R_BioCondManual
If I go back to my pre-R era I would follow the above. I think its a good kick-off for those who want to learn R and start getting familiar with R's environment. I hope it helps you =)