For my second installment of updating my sidebar to make it more useful for those seeking to find online resources for ancient manuscripts, texts, and translations, I have now added a section for Nag Hammadi and Relate Literature. For manuscripts, all I have are the Tchacos Codex high resolution photographs. If the digitized manuscripts Nag Hammadi Codices, Berlin Codex, etc., are also online, I am unaware of it.
I didn't see anything for the Coptic text itself online. But there are a couple online translations. I have a link to both English and French translations of the Nag Hammadi Literature.
If anyone has any other links for texts or translations for Nag Hammadi and related works, please send them to me and I will add them to my website.