RStudio Rnotebooks
So I have been using Rnotebooks since October. I have been using Rmarkdown for a year or so before then. I really like Rnotebooks for doing reproducible research. What that means is that you can have your report and analysis all in one document. So if you make any changes you can update your notebook and all of the analysis will be updated with the report.
Have written lots of reports using the standard Office Software and make lots of mistakes updating my work. With Rnotebooks there is less of a chance for these mistakes.
Try the tutorial from RStudio Rnotebooks and you will be well on your way. Here is the link to the RStudio IDE Cheat Sheet and the R Markdown Cheat Sheet.