Truth is perfect and complete in itself. It is not something newly discovered; it has always existed. Truth is not far away. It is nearer than near. There is no need to attain it, since not one of your steps leads away from it. Don’t follow the advise of others; rather, learn to listen to the voice within yourself. Your body and mind will become one, and you will realise the unity of all things. Even the slightest movement of your conceptual thought will prevent you from entering the palace of wisdom. The Buddha meditated for six years; Bodhidharma for nine. If such effort was required of these ancient Masters, how much more is required of you. Your search among books, sifting and shuffling through other people’s words, may lead you to the depths of knowledge, but it cannot help you to see the reflection of your true self. When you have thrown away all conceptions of mind and body, the original person will appear, in all his fullness. To obtain the inestimable benefits of meditation, you should first make a firm decision to practice everyday.
Your meditation room should be clean and quiet. Wear loose clothing and remove your shoes. Sit on a cushion, with legs crossed, in as comfortable a manner as possible. Keep your back straight. Don’t lean to the left or right; don’t tip forward or bend back. ……Breathe through your nostrils. Before you begin meditation, take several slow, deep breaths. Hold your body erect, allowing your breathing to become normal again. Many thoughts will crowd into your mind. Don’t dwell on thoughts of good or bad. Don’t desire to attain enlightenment. Let thoughts come and go, without getting involved in them or trying to suppress them. Think the unthinkable. In other words think no-thinking. Meditation is not a way to enlightenment, nor is it a method of achieving anything at all. It is peace and blessedness itself. It is the actualisation of wisdom, the ultimate truth of oneness with all things. In your meditation, you yourself are the mirror reflecting the solutions to your problems. The human mind has absolute freedom within its true nature. You can attain freedom intuitively. Don’t work toward freedom; but allow the work itself to be freedom. When you want to rest, move your body slowly, and quietly stand up. Practice this meditation in the morning or in the evening, or at any leisure time during the day.
Actually i think the idea that just sitting is enlightenment came from the above passage. The bolding is mine.
I have been a student of zen/chan for about 20 years, its been worth the effort, and in some small way i think i may at times approach the ideal of "just sitting" as outlined in the above quote.
If you are going to get some understanding of zen, or any tradition for that matter, you will need longer than a month and should probably contact a teacher of that tradition. If you are looking for a zen / chan teacher i would look for one that uses both rinzai and soto techniques. I have read that many of the great teachers, including dogen, used both kinds of methods.
EDIT: Thank you to the OP for inspiring me to look this up, i havent read it in a while and its one of my favorites
EDIT: i actually like this translation better http://www.dailyzen.com/zen/zen_reading0401.asp