R for Data Science - great, modern treatment of many fundamental R topics using the tidyverse approach
R Cookbook - not quite as up-to-date, but very thorough
Cookbook for R - dated, but the graphing section has some great ggplot2 recipes
Stack Overflow is the preeminent Q&A forum for programming, data science, statistics, etc. If you Google an R question, you'll likely land here. Over 21 million questions have been asked to date, with nearly half a million specific to R.
Stack Overflow for statistics (also called Stack Exchange or Cross Validated)
TWS Biometrics Working Group Resource Repository - an in-progress clearinghouse of dozens of resources (e.g., code, tutorials, video courses, etc.) for many topics related to wildlife statistics and data science
Population Modeling in Ecology - great set of instructional videos and scripts by UW's Gabe Barrile covering fundamental wildlife models (e.g., occupancy, mark-recapture, N-mixture models, etc.)
Statistical Methods of Estimating Abundance in Ecology - recorded workshop and materials focused on abundance estimation (i.e., N-mixture models, distance sampling, and mark-recapture)