I have a question regarding what tense form should I use to refer to an earlier self publication in a monograph chapter. For example, if I want to say (in the chapter), "most of the results were published in ", is that OK? Or should I use the present perfect tense?
I would generally go with "are published", since "were" would suggest to me that the results are no longer published. In some odd situations "were" might be better, for example, "the results were published online , but the website has been taken down". Similarly, in a case like "the results were published in the first edition , but have since been removed", I think "were" might be better since although the results are still technically published in the first edition, the point is to note that they are no longer published in the second edition.
Yes, writing "Most of the results were published in ." is OK.
Bonus tip: Don't treat citations as nouns / noun phrases. Instead, if you delete the citation, the entire sentence should still make sense and be grammatical. Thus, better style is to say "Most of the results were published by Smith et al. ." (for example).
For more elaboration, see http://www.read.seas.harvard.edu/~kohler/latex.html#refnoun, which is part of Eddie Kohler's excellent tips on scientific writing and using Latex.