You are correct that I urge caution before rushing into meditation on our chakras or practicing pranayama. Undesirable side-effects can develop if the practice is not done correctly. Ideally, you would want to find a local teacher who can get to know you and guide your practice. However, if that is not possible you may want to learn a bit more before starting on your own.
Paul's DVD is a great resource. I would encourage you to also obtain Dr Motoyama's book, Awakening of the Chakras and Emancipation. In this book, Dr Motoyama explains what happening during your practice, how to practice and what to be aware of. For example, Dr M states that the ajna, svadhistana and muladhara are the most important ones to work with first. Before you begin each session, you may want to do 8 cycles of Nadi Shodana, to balance your energies. [
http://www.yinyoga.com/ys2_2.2.7.2.4_nadi_shodhana.php]
To start a practice, go slow. Paul offers some simple meditations that should be safe: the practice of Hamsa (or So'ham) chanting while you bring your awareness to the chakras. Try this for a few months and see how it goes. Pay close attention! Not just when you do the practice, but during the day too. Notice what is changing, if anything. This can be the start.
If you feel that the practice is causing you problems, you may be able to find someone close by to help you by checking with Spiritual Emergence Service at
www.spiritualemergence.net (for Canadians) or
www.spiritualemergence.info (for Americans)
I hope this helps.
Cheers
Bernie