R is tough at the start, probably for longer than the start. I was completely new to any form of programming or indeed statistics beyond the rudimentary teaching at medical school that noone paid much attention too. However, thrust into a genomic scale PhD i found it almost mandatory to know something about R and statistics to convert data into knowledge. That said, one can try to leave it up to the purer bioinformaticians but its nice to have overlapping abilities and a way of deciphering certain research papers.
This book was my second book in R. The first was Beginning R, in the same series. I think they complement each other quite well but the first book is the weaker of the two, but still a relatively gentle introduction. This book also has excellent introduction chapters that might be enough for the savy given the wealth of additional material for free on the internet anyway.
The structure of this book is logical and whilst not going into statistics in vast amounts of detail the writing is so lucid and crisp that it feels like the information imparted is of a much greater tome.
I think going on an R course whilst reading this and the beginnings book is about the easiest way of entering the world of R. For more brief encounters one could simply just use individual packages without revising the whole of stats/R. Another good book in the series for the genomically orientated is the bioconductor case studies, although they all need modernising into the post-microarray, high throughput sequencing world.