The Share Reiki International Forum http://www.sharereiki.org is an excellent site for people new to Reiki as well as those who've been around the block. I used to meditate on the mandala which Pat Lusher forwarded since the site's been updated.
If you go to the site's index page (HOME page), look under the category of 'Distant Reiki' and the Reiki Healing Reservoir discussion is listed. You can donate as well as receive Reiki from the Reservoir.
Relax and take a deep, long breath expanding and contracting your belly. Gaze for 30 seconds on the centre of the mandala, close your eyes and let the energy flow into your body. The beautiful heart mandala will help you to open yourself for the Reiki energy. Use the link as much as you like.