As u have not utilised ur 11th class effectively, now u have to read for atleast 10-12 hours per day, allotting 3-4 hours for each subject on an average (dont be tensed, if u aren't habituated to work for long hours, start practising it right from today, i'm sure u'll love to spend time with books as u get closer to them). Also be motivated towards ur goal every moment, if dats lost then u will not gain anything whatever be the time u spend in studies.!
I guess u might have already bought all the required materials and text books by now. Make sure that u solve each and every problem from all these books (atleast make sure that u've gone through all the problems). Don't read for jee now, u can prepare for it from jan'10. Study to learn concepts, to know new things and that makes ur education interesting. :)
Almost every institution makes sure that the teaching part gets completed by december. U must also complete learning 80-90% of concepts by december (u can do it in these 9 months, if u utilize each day effectively).
Another important thing, try minimizing ur internet time to as much extent as possible. even don't spend much time in discussion sites like targetiit, goiit etc., just come to clarify ur doubts. And after dec.'09, use targetiit extensively for next two months viz., jan & feb. that helps u a lot in revising ur concepts by solving different kinds of problems everyday. Again, minimize ur online timings in march and get back to previous year jee questions and solve them effectively. That's it. U'll succeed in the race.
All d best... :)