for sentence correction :
there could be no other book than manhattan gmat sentence correction guide, it states all the grammer rules properly followed with exercises regrarding the same.
then og is very good for verbal as well
spideys notes & 1000sc are available in this forum which will be of great help as well.
for critical reasoning :
you could start with kaplan or princeton to understand startergies.
og again gives you enough practise.
for reading comprehension:
i guess og shall be more than enough.
verbal is like quant, more you practise the better you get.
i am sure if you concentrate on verbal you will score a great score.
all the best