• think about the topic ... understand all aspects, etc.

• find out what others have done before (reading required)
  ( Google Scholar ... Citeseer ... DBLP ... Wikipedia(?) )

• consider what's need to evaluate your work
  (don't bother considering evaluation-by-bluff ... it doesn't work)

• make notes on everything that you look at/think about

• set up a thesis web site? (for holding the notes)

• meet your supervisor and find out what they expect

• establish a consistent Thesis working pattern (weekly meeting?)

Do all of this before week 6 and assignments get heavy.