True that that website recommendation is for longer term study but a word of warning - there is no short term way to prepare for IELTS if you don't have the level of English. I teach a variety of formats for IELTS, including 1 day and 1 month courses, and candidates without the English necessary never do well. Studying from lots of practice books will not do it. So plan ahead, give yourself lots of time, and build your English up first.