For now until the villages become fuller every jonin will get 1 genin to teach. Unless there is a jonin who does not want a genin to teach. They will range from one to three genin to teach. After pupils reach Chunin rank they no longer need a sensei, however, they can still be taught by there former sensei.
The sensei may get a raise in pay for teaching but will also go on lower missions with their students. This is the reason why they get a pay raise. Sensei can go on missions without his/her pupil(s) however pupils cannot go on missions without their sensei unless the mission is a lower rank then themselves. If they are the same rank as the mission then the pupils can go as a squad without the sensei however this can only be done when there are three members in a squad.
Sensei's get an additional 200 yen with their weekly paycheck. Must make note of this in your weekly pay.
Sensei are required to teach there genin students at least three jutsu, however this does not mean the students gain them automatically the students will have to formally post learning these techniques instead of buying them. They will still get them with a shop transaction but they will be free of cost. Jutsu learned from sensei will have a post length minimum depending on jutsu rank.
D Rank jutsu will have a post minimum of 150 words. C Rank jutsu will have a post minimum of 200 words. B Rank jutsu will have a post minimum of 300 words.
Also the rank system still applies! This meaning that D rank Genin cannot learn or be taught A or S rank jutsu, etc...