What resource do you use to research usage of computer terms, such as "checkbox" versus "check box"?
If you are trying to get a sense of the relative frequency over time of two or more alternative spellings, you may be interested in the Google Ngram tool, which reports on the frequency, year-by-year, of specified search terms in the Google Books database. Here, for example, is the Ngram chart for "check box" (blue line) versus "checkbox" (red line) for the period 1975–2005:
The Ngram tool uses the year of publication specified on the title page of each book included in the search in gathering data for the frequency plot. You can also see examples of the search terms in situ by clicking on of the year intervals listed beneath the Ngram graph here.
There are a few starting points if you're making a decision about the usage of computer terms.
The Microsoft Writing Style Guide (formerly the Microsoft Manual of Style), which they pitch to people who write about computer technology, is a comprehensive guide for computer terminology. They have articles like this that provide guidance for check box:
Use check box, not box or checkbox, to refer to a check box in UI.
The IBM Style Guide, while older, has a lot of recommendations on specific usage, and approves of the form check box.
The A11Y Style Guide provides guidance on web design. While it is more focused on design, it models usage: it has an entire section on forms, where it refers to checkboxes.
The Apple Style Guide may also be useful, but I've never used it.
Other companies may also have their own style guides, whether they are internal or shared for use with the public. As you can see, even with a simple example like check box / checkbox, they disagree on usage. If you are writing for a small company or a venue that lacks its own style guide, my advice is to compare results, decide on your own preferred usage, and apply that usage consistently in your own documentation.
You might want to consider a dictionary that's carefully curated and recent. The more recent it is the more likely newer terms will be listed and updated usage is covered. Careful curation is necessary because terms may have different meanings both outside the field of computer science (e.g. kilo meaning 1000 vs 1024) and even different definitions within computer science (e.g. the word glitch).
I'd suggest Wikipedia as a source that's recent. It's not carefully curated per se but since everyone can add to it, it's very likely that a term you're looking for is mentioned, possibly in different contexts. In addition, it's a good start as it probably links to other sources (depending on what you're searching for those may be original papers that coined a phrase or came up with some new word).
A more curated reference is a dictionary from an established publisher. For computer science, I found A Dictionary of Computer Science (7 ed.) published by Oxford University Press. It's fairly recent with this (latest?) version dating from 2016.