Unfortunately, we do not have an official key explaining all of the tools incorporated into the Artscroll Schottenstein Talmud. However, here are some helpful tips for navigating the translation page's font styles that may prove especially helpful to newcomers:
BOLD CAPS: Direct quote from a Mishnah or Baraisa
Bold: Literal translation of the Talmud words
Regular Text: Artscroll's added elucidation
Italics: Transliterated words, or the translation of a biblical verse
These styles may be combined. For example, if there is a transliterated word (Italics) which is also part of a direct Mishnah quote (BOLD CAPS), it will appear in BOLD CAPS + ITALICS.