Leave the DVDs alone and actually learn the basics. So as to get a rounded overview you might want to look at
this FREE PDF and from there, pick-up the primary foundation tools; 13 Steps to Mentalism by Corinda and Annemann's Practical Mental Magic.
UNDERSTAND that Mentalism is a kindred art form to magic and not one in the same and that 90% of what you see people doing now days under the header of being "Mentalism" AIN'T! It's either mislabeled Bizarre Magick or what we call Mental Magic; routines that are obviously tricks even to the mind of the laity. Mental Magic is far more commercial because it is seen as "safe" simply because it looks like a TRICK whereas Mentalism, when executed properly, leaves the observer with no sense of logical explanation, even the trained mind can be seriously fooled when faced by a solid student of mentalism
There are two chief schools of thought within this arena as well; the Older (original) mode of approaching Mentalism leaned heavily on the esoteric with many acts being billed as demonstrations in Telepathy or Clairvoyance, etc. By the mid-20th Century the antics of Joseph Dunninger took route giving us the first phase of Modern Mentalism which gave us a more analytical sense of perspective. Though this had existed for a great number of years, it would be Dunninger that would take the idea into the modern era followed by Kreskin who seriously commercialized the approach under the guise of being a Paranormal Researcher.
With the advent of David Blaine & Criss Angel in the mid-1990's Mentalism was quickly bastardized so as to include a huge amount of Bizarre Magick that was mis-labeled as such -- Stigmata being a prime example -- but then the real insult is when young people refer to David Copperfield as being one of the greatest "Mentalists" in history . . . "sigh"
Shortly after Blaine & Angel hit the scene Derren Brown surfaced in the U.K. and added the jaded elitism that so common of the Brits when it comes to supposed intellectual superiority and the imposition of "rationalism". While Brown was the first to slap the believer in the face and in essence mock them via his demonstrations, he was certainly the new example of such; Penn & Teller (Penn specifically) being the poster kids of this style of abuse and public insult or as some of us look at it,
the Evangelists of Atheism. The promotion of an attitude and approach that is costing the whole of magic presently, when it comes to public trust and general public image. While you may not have a sense of personal spirituality you may want to look at the fact that you're the minority and it's kind of dumb to piss in the pool in such a case.
This "New School" of Mentalism sacrifices many of the proven tools that have been used within the industry for decades, such as Home PSI Parties, working Lectures & Workshops, and most especially the act of doing Readings. Quite boldly people in this mode of thought have stated that their agenda is to do away with the more esoteric ties the craft has known over the past 130 ish it's been around. Which means they wish to neuter the art and make it nothing more than magic tricks; a for certain opposite from where Mentalism has been for a very long time, the chief psychological dynamic of Mentalism being to invoke belief vs. suspension of belief such as we find in traditional magic.
BTW. . . I'm one of the few characters in today's Mentalism world that will give you this better rounded sense of perspective. Not because I'm the only one that sees things in said manner but because I'm one of the few that's willing to be the paddle boy, the others having grown sick & tired of the constant harassment and arguments offered by those that simply don't get it.