The Digital Madoushos and Mon+amour are two different entities created by Mana, both highly regarded in fan communities.
Although no longer functioning, Mon+amour was considered "The Mana Official Eternal Society"-- a fanclub anyone could join with an anual fee which provided small 12-24 page booklets of photos and writings as an insight to Mana's life along with his activity in Moi dix Mois and Moi-meme-Moitie.
Upon entry of Mon+amour, members would receive a binder along with their first Madousho so they could file the rest of the year's booklets with a total of 10 booklets sent out per year.
Other perks of being a fanclub member involved priority concert tickets and chances to enter contests and win prizes from Mana himself.
While the fanclub itself was called "Mon+amour", the monthly booklets fans would receive via postal mail were known as the "Madousho", meaning Grimoire in English.
Fundamentally, Mon+amour was only available to Japanese fans until around 2005 when Mana's popularity rose overseas. At that point, CDJapan hosted an English translated version where fans could sign up and receive the Japanese booklets and read the English translations online simultaneously. However, this only lasted a short time until this English fanclub was controlled completely by Midi: Nette via its own site and registration system.
Unfortunately over the next five or so years Mon+amour struggled to keep up with its supply and demand as a service and closed down at the end of 2011 for both Japanese and foreign fans alike. In February 2012 Mana announced a new system on his blog known simply as the Digital Madousho.
The Digital Madousho is the exact same concept as the old booklet form, but instead of receiving physical Madoushos and paying annual membership fees, the Digital Madoushos have become a pay per article system completely online.
Currently Digital Madoushos only serve to the Japanese speaking Mana fan base (there are no official international translations) so those who are interested in joining should be forewarned if you cannot read Japanese.
Every time Mana releases a new Digital Madousho, fans may choose to purchase the newest release as well as previously uploaded Madoushos, each 500 yen (approx. $5 USD) There are no annual or monthly fees to the new system, just simply 500 yen per Digital Madousho article you are interested in reading.
For those who would like to join but cannot speak Japanese, feel free to look through my "Digital Madousho English Tutorial" with translations of the entire process of purchasing of Digital Madoushos.
Digital Madousho Registration Process: English Tutorial