Need to get faster

Hi There, I recently asked a female friend what she could do 100m in, expecting to be maybe ten secs behind as she is what I would term a good swimmer. Unfortunetly my 1.40 paled when compared with her 1.15. I consoled myself with the knowledge that I have only been swimming 1 year and I have been mainly TI drilling concentrating on Technique. Now it is time for speed. I have started to compete in sprint tri's so I am looking to get around the 6min mark for 400m. I have can swim most days and my local pool is 33m in length. Can anyone show me the way? Thanks for your time Dec