Where to identify sources in your writing?

There is very little information on this subject on the web, but in general:
If your sources are very important to your ideas, you should mention the author and work in a sentence that introduces your citation. If, however, you are only citing the source to make a minor point, you may consider using parenthetical references, footnotes, or endnotes.
-Plagerism.org

In my experience reviewing literature, I have found that if you are paying tribute to a particularly novel idea or theory you probably should cite them at the beginning of the sentence, usually before writing on their novel idea or theory.

E.g., Marchetti (1977) proposed that directly injecting CO2 into seawater below 3,000m, given average temperature and pressure, will sink to the ocean floor.

In my experience, putting the source at the beginning of your sentence, negates the necessity to reference the source parenthetically at the end of the sentence (e.g., Marchetti, 1977). Note: this does not negate the need to reference them in your references, bibliography, or literature cited.