This page has a few starter resources for string players new to reading music!
On a violin, viola, cello or double bass, you have four strings, and each of those strings gives you a different note.
To make other different notes, you use your left hand fingers to push the string against the fingerboard, in different places. This changes the length of the string which is free to move.
(Unlike with a guitar, you don't have frets to define the places for you - so you just learn over time, by listening and practising, where your fingers go to make each note.)
If you don't put any fingers down to change the length of the string, then you get the lowest note which that string can play, when the longest possible section of it is vibrating, all the way from the nut to the bridge. We call that the "open string".
Beginner string music often has a lot of open strings, because those are the easiest ones to play :-)
I think if you're a string player, a good first step in learning to read music is to get familiar with what your four open strings look like on the page. Then, when you're looking at a page of dots, even if you can't recognise all of them yet, you've got a few familiar landmarks to start with.
I'm not saying actively try to memorise them straight off. (Only do that if it suits your learning style, and isn't going to stress you.)
What I recommend is more like: every now and again, let your eyes roam over the shapes, and notice where the notes sit on the lines. Or simply play each note in turn on your instrument, while looking at the matching one.
Here, I've supplied each instrument's "open-string picture" in two different file formats: one better for putting on a screen, one better for printing out, if you want to.
I suggest that you think of some good places to put these pictures, where you'll see them a few times each day! Possibilities include wherever you'd be while your kettle's boiling, on the wall near your bath or loo or TV or wherever you practise playing, on your phone lock screen or computer desktop (or TV screen if it lets you have a default picture), or the wall or ceiling above your bed. Especially good places are anywhere you'd be waiting around anyway :-)
Tips for saving the pictures from here, if you're not very techie:
The ones for screens are the ones you can actually see on this page. If you do a right-click or a long-press on the one you want, you'll probably get a little menu up which asks if you want to "save" it. Then you can do whatever you could do with a digital photo, e.g. put it as the lock screen of your phone. (But I can't tell you how to do that part!)
The links go to PDF (Portable Document Format) versions, which are designed to print onto A4 paper. Some computers or phones will let you open the files directly by clicking on the link, and you can print from there. Or you can right-click or long-press on the link, and it'll probably ask you if you want to download the file.
Jump straight to your instrument if you want:
(Cello is also known as Violoncello.)
PDF of double bass open strings
(4-string bass guitars have the same open strings as the double bass, so this one could be useful to bass guitar players as well :-) )
I know there are lots of music-learning apps and web sites these days. I haven't looked into them recently, but if people want to recommend their favourites, we could maybe crowd-source a list to go here.