One resource that is really helpful for beginner energy work and breathing exercises is "Your Hands Can Heal You" by Stephan Co. I think some of the concepts behind building up Pranic energy through specific breathing rhythms is very useful.

I have tried a few general techniques but one that I can never handle is the 4-7-8. Has anyone else successfully accomplished this? I found out about it a few weeks back but I have been battling a terrible cold which I think is part of my problem in tackling this.

I've never heard of the breathing technique that Angel mentions, but I do know of a breathing method called the Fourfold path. I am also uncertain of the 4-7-8 rhythm that you mention, Averina. Is there something special about this pattern?