R. Yaakov Moelin, known as the Maharil, was recognized as the supreme halachic authority for Ashkenazi Jewry in his day. His customs, collected in Minhagei Maharil (and cited often by R. Moshe Isserles in his comments to the Code of Jewish Law), are the basis for the conduct of Ashkenazi Jewry in many areas of Jewish life, especially in matters relating to prayer and synagogue procedure.
Links: Rabbi Jacob Halevi (Maharil), The Origins of Tashlich (a custom documented by Maharil)
As the last month of the Jewish year, Elul is traditionally a time of introspection and stocktaking -- a time to review one's deeds and spiritual progress over the past year and prepare for the upcoming "Days of Awe" of Rosh HaShanah and Yom Kippur.
As the month of Divine Mercy and Forgiveness (see "Today in Jewish History" for Elul 1) it is a most opportune time for teshuvah ("return" to G-d), prayer, charity, and increased Ahavat Yisrael (love for a fellow Jew) in the quest for self-improvement and coming closer to G-d. Chassidic master Rabbi Schneur Zalman of Liadi likens the month of Elul to a time when "the king is in the field" and, in contrast to when he is in the royal palace, "everyone who so desires is permitted to meet him, and he receives them all with a cheerful countenance and shows a smiling face to them all."
Specific Elul customs include the daily sounding of the shofar (ram's horn) as a call to repentance. The Baal Shem Tov instituted the custom of reciting three additional chapters of Psalms each day, from the 1st of Elul until Yom Kippur (on Yom Kippur the remaining 36 chapters are recited, thereby completing the entire book of Psalms). Click below to view today's Psalms.
Chapter 64
Chapter 65
Chapter 66
Elul is also the time to have one's tefillin and mezuzot checked by an accredited scribe to ensure that they are in good condition and fit for use.
Links: More on Elul
What is a mitzvah?
An act of uniting heaven and earth.
But heaven is spiritual and earth is material. To make spirit and matter one is impossible!
A creature of earth cannot make earth heaven. And a heavenly being cannot bring heaven to earth.
But for you, it is not impossible.
This mitzvah that I am commanding you today is not impossible for you. It’s not even distant. It’s very close to you, in your mouth and in your heart to do it. (Deut. 30:11)
It is close to you because the Torah was given to you both written and orally. (Rashi)
Because within you breathes the Creator of both heaven and earth.
So that when you speak the words of His written Torah, you bring heaven down to earth.
And when you explain the words of His oral Torah, you bring earth up to heaven.
Indeed, you accomplish the impossible every day.