There is no standard that I am aware of in any of the jurisdictions, it is based upon when the priest (through his charism -gifts of the Holy Spirit-given at ordination) determines that you are ready. The priest often looks at many things including your participation in the Liturgical and community life of the parish. He may assign readings and discuss them with you or require you to attend scheduled catechumen classes.
In my parish we have a standard catechumen program in which we first ask that the Catechumen fill out this questionaire:
1. What was your previous religious background (Denomination, Christian or non christian---Jewish, Moslem, Hindu, Buddist, etc, agnostic, or atheist)?
2. Were you raised in home in which religous belief was important or unimportant?
3. Are you married, divorced, engaged, or single? Do you have any children?
4. Do you have any family or friends who are Orthodox Christians?
5. What raised your interest in learning more about the Orthodox Christian Church?
6. Are there specific topics you wish more information about the Orthodox Church?
7. What books have you already read about the Orthodox Church?
After that we then develop a personalized catechumen program which has as its basis the following program:
1. Attend at least 20 sessions of Orthodox Instruction on Saturday afternoons.
We offer weekly catechism classes that include a 2 year history and basic of Christianity, a 12 session monthly Orthopraxis class The practice of Orthodoxy---the how-to- dos so to speak, and special event speakers.
2. Attend the services for 8 out of the 12 great feasts during the liturgical year. The services of the Great Feasts include the Vespers of the Feast, Orthros, and the Divine Liturgy. Attendance at any of these entail attending the services of the feast. If the Feast happens on a Saturday or Sunday, you would be expected to attend as many of the services as possible. The Twelve Great Feasts are:
a. Nativity of the Virgin Mary- September 8th
b. Elevation of the Precious Cross - September 14th
c. Entrance of the Virgin Mary into the Temple - November 21st
d. Nativty of Our Lord - December 25th
e. Theophany of Our Lord -January 6th
f. Meeting of Our Lord into the Temple -February 2
g. Annunciation of the Virgin Mary -March 25th
h. Entry of Our Lord into Jerusalem - Sunday before Pascha
i. Ascension of Our Lord -40 days after Pascha
j. Pentecost -50 days after Pascha
k. Transfiguration of Our Lord -August 6th
l. Dormition of the Virgin Mary-August 15
[Note Pascha is the Feast of Feasts and is not included as one of the Great Feasts as it outranks all of them---it will however count as one for the task purpose]
3. Read four books about the Orthodox Church or the Orthodox Christian life. [At this point suggested books are provided that include a basic catechism of the Church and other books based upon needs shown in the questionaire. for example differing books are given based upon the background, interests, and Orthodox books the catechumen has already read.]
4. Participate in the services of the Church on a regular basis. This of course is without need to explain, attend Church services when you are able to, and participate to your best ability singing, praying, and supporting others in prayer.
5. Contribute to the life of the parish through gifts of time, talents, and money. Establish a regular giving of alms to the poor, fasting, donating of your surplus to the church general fund, look at your talents and offer the organizations of the church your services and blessings of your talents.
If the person is married and the spouse is entering the church additional readings that will provide an Orthodox foundation for their marraige are provided.
If there are small children in the home readings to help the parents catechize their children will be provided.
Many parishes do it differently but in all it is always the priest who leads the catechumenate, even if there is a parish Catechumen director (like myself) who tracks the progress.
Oh yes, don't be afraid to ask the priest to baptize/chrismate you when you think you are ready. He may say yes you are ready or no and update you on where he sees you in your catechumenate.