Defining coordinate system/projection of raster

As you can tell from this question I am a total GIS beginner. I have downloaded bioclim data from worldclim and imported the file into R:

temp <- raster("bio1_16.bil")

> temp
class       : RasterLayer 
dimensions  : 3600, 3600, 12960000  (nrow, ncol, ncell)
resolution  : 0.008333333, 0.008333333  (x, y)
extent      : 0, 30, 30, 60  (xmin, xmax, ymin, ymax)
coord. ref. : NA 
data source : /.../bio1_16.bil 
names       : bio1_16 
values      : -116, 234  (min, max)

So it seems that the coordinate system is missing. First off, how do I find out which type of projection has been used? And then, how do I assign it? Googling has brought up something like

CRS("+proj=longlat +datum=WGS84 +ellps=WGS84 +towgs84=0,0,0")

but frankly, I do not understand what that means, so how to get from no info to correct projection and eventually to the correct R command? Is there something like a cheat sheet?