i guess its a good idea to make reservations
If your looking for a set direction and timetable on where your going, then yes book away, this might save you some money, and will also ensure that you will have a roof over your head for that night.
As for it being wise all then time, for you, it might be, but for me, I will reserve for a couple nights before I go and a couple when I am leaving. What happens in between is up to me with no time table or set destinaion. It just adds a little spontinaity to my trips, it creats some unknowns.
As for how far in advance to book, if you going away between Mayand Sept, book it ASAP, If you book it through this site
then you can cancel with 24 hours notice if I remeber correctly and not be charged. That way if you plans change bewtween the time you book and the time you go away, you can just cancel with the secuity of knowing you have a place to stay while you away.
Hope that helps ya some