As a note, please give your forum threads descriptive titles in the future, to make the topic clear. For example, this thread could be named "How do I make an English voicebank?"
For an actual answer, there are several options for english voicebanks. Because English pronunciation is complex, all methods will write the sounds phonetically.
The most popular methods are PaintedCZ's custom reclist (VCCV), the ARPAsing method, and Delta's XSAMPA reclists. These are also supported by OpenUtau's phonemizers, so once you finish recording and configuring the voicebank, you'll be able to use it by typing plain english words into notes.
VCCV has a full tutorial series on YouTube.
ARPAsing has a dedicated website for tutorials and download links.
ARPAsing Resources and Directories: One stop shop for everything ARPAsing
arpasing.neocities.org
Delta wrote the tutorials for their XSAMPA reclists in Japanese, and so far just the download page for the reclists has been translated.
Table of Contents Overview List Principles Vowel Pronunciation Consonant Pronunciation
tl.tubs.wtf
There's also a lot of lesser-known custom English reclists. I've also heard many people use CV-C (a multilingual reclist) and SEL/MEL. Right now I'm involved in beta testing for Salem's CVVC reclist. And it's pretty common to just add English extras to a Japanese voicebank.
You've got a lot of options to explore, so before you start recording, I recommend downloading existing English voicebanks and using them. You can gain experience using the different systems and seeing which one you prefer. English banks are a big commitment and typically require about 1000 recordings and 3000 otos, so pick the one you'll enjoy the most.