Two I like to suggest using for a newtonian ie dob
The first one is very good to get the mechanical side of collimation going ie using a screwdriver to align the smaller secondary mirror near the top and then adjusting the bigger primary.
Take your time with the first link and do during the day.
This will get you to a stage of lets say 90% collimated and will do you for now.......fast forward a few months, you want your stars to focus pin point, your are imaging at high magnification and you want the image to be crystal clear etc etc ie you are getting a perfectionist!!!
This is when you star to get into the second article. It is about star testing. I hve been into the hobby 7 months and still am trying to perfect this seconf method.
So here they are
Easy starter:
http://www.schlatter.org/Dad/Astronomy/collimate.htm
Fine tuning:
http://www.schlatter.org/Dad/Astronomy/collimate.htm
Good luck and please ask lots of questions