I don't know about Perl, but if you want to get up and running with R for some basic data analysis, I'd say: 1 week to get used to the syntax and do basic data

I don't know about Perl, but if you want to get up and running with R for some basic data analysis, I'd say: 1 week to get used to the syntax and do basic data manipulation such as contructing, editing data frames, reading and writing files etc. You can also get going with the simple graphing functions quite quickly. 1 week to learn the statistical stuff - scatter plotting, correlations, linear regression modelling. Of course, I'm talking about just learning the basic syntax. Doing regression properly could take a long time to learn. The R Book by Crawley is quite a good introduction, especially if you want to brush up on some basic statistics. It's not very in-depth though, so you might have to move on to more advanced texts after a month or so.