Miscellaneous doubts

Hi

I often face grammatical obstacles while communicating in English. Though I am pretty confident with my command over English, I still have some minor doubts. Some of the doubts are as follows:

- Should it be "Some of the doubts are as follows:" or "Some of these doubts are as follows:"
- Should it be "Researchers have discovered a new gene." or "The researchers have discovered a new gene."
-Should it be "The article presents a discussion on genetic transcription." or "The article presents a discussion about genetic transcription."
-Is the following sentence right? "Following is a list of books on assorted topics:" Can the word "assorted" be used in this context?

These are some of those doubts that arise out of my day-to-day affairs. I am desperately seeking for some expert guidance to help me come over such silly obstacles, which makes me feel unconfident to communicate in English. I shall keep updating this forum with my doubts so that others also get an opportunity to refine their English (in case, there is a need to).