If there is a conflict between the APA guidelines and those in your university manual, ask your advisor which to use. You may find that the university has simply adapted APA and added some refinements.

This "Turabian" question comes up again and again. Kate Turabian wrote an excellent guide to scholarly writing, and her book has come to be known informally as "Turabian". It is my position that you should stick to the official APA Format guidelines for your dissertation. You can purchase the APA Format at any bookstore, and you can find updates (on new formatting issues such as how to cite internet sources, for example) at the APA website.

You want a topic that is appropriate to your degree and to your personal interest or field. More critically, if you are doing an empirical study (and most doctoral candidates are), your topic must be appropriate for the subjects you have to work with. For example, if you do not have access to a large group of teachers to whom you can administer a standardized test and/or a questionnaire, you cannot do your dissertation on "Teacher attitudes towards parental involvement". Similarly, if you do not have access to a good sample of auto mechanics, you cannot do your dissertation on "Self-esteem Variables in Auto Mechanics".

Of equal importance in topic choice is that it be narrow. You cannot do a dissertation on "Homework". You can write about "The Effects of an Innovative Program of Parent Involvement in the Homework Activities of Fourth Grade Boys in an At-Risk School District in New Jersey".

And finally, your advisor is actually giving you good advice! "Do a search" means start gathering and reading the scholarly literature on your topic. Become familiar with both the theoretical and empirical materials, and start to formulate a framework. Do your Literature Review. Only then will you be able to formulate narrow questions and hypotheses.