Reddit mentions of Scanning and Transmission Electron Microscopy: An Introduction

Those books are definitely geared toward materials science. If you're interested in the operation of TEM, though, it should be helpful. The physics behind the instrument don't really change. In a virology lab, you probably work at lower accelerating voltages, and you might not be doing atomic-resolution work, so those bits wouldn't apply to you.

This book is cheap and discusses biological applications, so it may be a better starting point. Some of the springer publications are nice resources, but they can be quite expensive. You might want to check your school library for any books you may be interested in. Also, some of these things can be found for free in PDF form if you search hard enough online.

Most of the books I've used to learn about TEM are for materials science or specifically STEM and Z-contrast imaging. Those types of resources may not be as relevant to you.