If you mean should you use a block of butter or a spreadable-type, I would suggest using the block - then you know you are just using butter and not a blend with vegetable oils or whatever.
Can I also suggest you look at Delia's complete cookery course? There are recipes for different types of pastry, one of which (for puff pastry) suggests grating the butter having taken it out of the freezer... and it works. I used it to make individual Boeuf en Croute and they went down a storm.
The other thing I would say is that usually the best pastry is made by those with the coldest hands, so straight from the fridge should be ok.
Finally, experiment! Find out what works best for you and produces the best results and then stick to it. It should be fun, too... and, after all, the proof of the pudding...