If I have strong professional IT skills but average educational background, will a university consider me for admission or financial aid?
Professional IT skills have very little to do with graduate-level work in computer science. While such skills may lead to a positive letter of recommendation, it is unlikely that you will receive either admission or financial aid (in the form of a teaching or research assistantship) solely on the basis of your record as an IT professional. There may be exceptions to this (for instance, if your professional work is in a specialized area that maps closely to an existing research area at the school to which you are applying), but in general, but that would be more the exception than the rule.
In other fields, such as bioinformatics and chemistry, where "professional work" may be more similar in nature to ongoing academic research, this is more of a possibility—I know several people whose work careers did have an influence on their admissions to graduate programs.