Wikipedia:Admin coaching/Guidelines
A glance at the Requests for Adminship page will show that there are no official requirements for becoming a Wikipedia administrator. Anybody can apply regardless of their Wikipedia experience. However this does not mean that there are no standards to be aware of. The reality is that adminship is evaluated in terms of communal trust and confidence, not percentages and numbers, and each editor will have their own way to assess a candidate's readiness for the role. While anybody can apply, a review of failed RfAs will quickly show that members of the community have many unwritten expectations. Applications that are judged to have little chance of success are often closed early; such failed candidacies illustrate cases where expectations clearly are not being met.
Areas where many or most editors may have expectations include the breadth and duration of experience, stability and professionalism as a community member (quality of interaction), and understanding of the Wikipedia ethos and main policies. Other signs of helpfulness or work undertaken in the community are also looked on favorably. Whilst no specific numbers exist for any of these, it is often possible to identify areas where a number of editors will feel that sufficient experience has not yet been obtained.
In short, RfA is a process of discussion and assessment.
The purpose of the Admin Coaching Project is to help ensure that potential candidates are adequately prepared for adminship. Generally your admin coach will review your edits and provide insight as to areas where you should get more experience, or changing your editing style, before submitting an RfA. Your coach will help you to assess potential stumbling blocks and help prepare for your RfA.
Whilst it is possible that you will be accepted for coaching or pass an RfA despite not meeting the basic criteria below, if the quality of your work and your ability to get along with others merits it, in many cases editors who are very much below RfA standard should apply for adoption as a first stage, before applying for admin coaching.