For an informal look, please see the Miniguide to requests for adminship and the more detailed page at Advice for RfA candidates.
Common areas where users may have expectations will usually be those that show:
Evidence of any concerns may also be raised and questions asked, for reassurance whether they will present concerns in future, and any other signs of helpfulness or work undertaken in the community will be seen positively.
The nomination process is not intended as a forum for voting on a nominee's popularity or strength as an editor. It is a forum by which consensus is generated on whether an editor should be given administrator privileges. An editor should not construe the outcome of an RfA as praise or condemnation of their efforts as an editor. Instead, it is an evaluation of their likely ability to appropriately use administrator rights.
An RfA is a very open voting process where your record will be looked at by experienced (and sometimes opinionated) users who have already made up their minds about what kinds of people they want as administrators. An RfA is open to everybody, including anyone you may have had disagreements with in the past, as well as new and inexperienced users you may be disagreeing with at the time.
Things that a potential administrator nominee should consider before accepting a nomination include:
The nomination process has clear instructions for constructing, accepting, and posting a nomination. A number of RfA contributors look askance at nominees who do not follow the instructions properly. Administrators are expected to read and follow policies. The inability to do this here is a bad sign. If something is unclear, then ask the person who nominated you, put a message on the discussion page of WP:RFA, or ask a user who has nominated someone else. Avoid mistakes rather than making them and then fixing them.
These points are not mandatory and there are always exceptions, but if you think back over your contributions and any of these is missing, it may be better to broaden your experience before an RfA.
There are also several other things that contributors will raise, such as whether you have an email address set. This is important for administrators, who may need to be contacted by users who have been blocked from editing.
Some editors have listed their individual rough criteria for support on the RfA standards page.