Is it better to read the Song of Fire and Ice books before watching the HBO series?

Would it be considered (though this is subjective) better to read the
Song of Fire and Ice books (at least the first two) before watching
the HBO series Game of Thrones or is it better to watch the series
first?

I would normally just wait to watch the series and then examine the
books, but it sounds like one would have to wait about a year between
each season (though this may be necessary for quality). I am very
interesting to know more about Stannis Baratheon and what will happen
with Renly Baratheon.

Does reading the books series cause a "spoiler" effect that hinders
enjoyment of the TV series or is it more interesting to see the
surprises and plot twists for the first time in the books rather than
on the TV series?