It took me about a week to notice smaller results...steering clear of the common illusion of having lived in your dream for hundreds of years, i had to recall every event slowly when i awoke, at first i would just spend a couple of days in my LDs but within months i was able to do it alot better. These days usualy once a month i'll spend about a year in one dream with 8-10 hours of sleep. but every saturday i'll spend a couple of months in an LD.
Its great because your ability to manipulate time keeps growing...pretty soon i'm going to conduct a test and see how far i can take it in one dream.

But i started doing all of this almost a year ago.