Hi Timhh ,
I am a visual observer and love using a rifle scope as my finder. The advise you have been given is correct. What happens is you have 2 images , one from each eye. The Red dot will be superimposed onto the starry back ground. Start by finding something bright and well known like the Alpha Crux or The Orion Neb . The eye which isnt looking through your finder will guide you to the object. When you get close the 2 images will merge and the red dot will glide over the object centring then becomes an easy process.When using magnification the effect becomes more pronounced.I have used a telrad many times. The trick with them is to get your eye in just the right place so you can see the concentric circles...
Hope this helps.
Zub