Some people will find that the saddle is perfect when they first buy it. Some people (including me) find that they need to break in a new leather saddle first. I budget about 500 miles for break in period.
I think that for every Brooks user, there is a different recomendation on the best way to break one in. I will just say that you do not want the leather wet, but slighty moist can aid break in. When it is about half way where you want it, then and only then do I apply Brooks Proofide. The Proofide makes it much more water repellent and that means that it will continue to break in much slower once you apply it. I apply that to both top and bottom, I set the saddle in the sun on a warm day to make it warmer so that it absorbs the Proofide faster. After you apply Proofide a few times when it is fairly new, after that apply every year or every couple of years.
Some people hate leather saddles, some people strongly prefer them (including me). I find that the B17 is too wide and flat in the back for me, I prefer the Brooks Pro or Brooks Conquest over the B17. But most bike tourists prefer the B17 or Flyer shape over the other models.
Saddle covers are not that bad. Free shower caps provided by some motels are also a favorite cover for some. I do not recall if the B17 uses the large or the small Brooks cover. I use the genuine Brooks cover and put it on the saddle as soon as it threatens to rain. It is quick to put it on and I do not even notice it is there.
Do not do what this guy did, in the evening he flipped his bike upside down so that he could check his tires for any glass or anything like that, and left his bike upside down all night. The thunderstorm went through at about 4 or 5am, by the time I took the photo the puddle that his Brooks had been sitting had drained, but his saddle soaked in a puddle for a few hours.
I put a cover over my saddle in the evening in the campsite almost every night in case there is any dew, but I think a lot of other people are not that careful and manage to get by. I was not going anywhere on my bike the day I took the photo below, the cover is still on the saddle to prevent it from getting wet from the dew.
Some people have tried and like the Brooks non-leather Cambium (spell?) saddles, I bought a couple and do not like them, I prefer the leather. But the Cambium ones are another option.