Over the years I have tried all sorts of methods for keeping lesson plans. I've had digital versions, lesson plan notebooks and three-ring binders. This is the set of documents that is currently working best for me. There are two parts:
The first part is the entire week of plans on one page. I customize this template to the year's schedule, then print about ten copies at a time to keep on a clipboard. I find it easy to see and write on in pencil that way. There isn't a lot of room but I don't need a lot of detail for myself. I type as much in ahead of time as possible, then write in the rest. I keep all of my supplies, papers, etc. for the lessons in one spot so not much detail is needed on the plan itself.
The second part is a template to use for guest substitute teachers. This is meant to be typed in so extra space for writing has not be left in. The form will expand as you type. Sometimes this fits on one page but many times it will expand to two or three pages depending on how much detail is needed. The idea here is to customize this to your schedule as well, then save one for each day of the week. I've included only Monday because it will save time to customize one, then "Save as..." for the other days. When you need a guest teacher, you just pull up the correct day(s) of the week and begin typing. Since much of it is already there it makes the job of making sub plans quicker and easier. In case of unexpected absences, the digital copy can be sent to a teaching teammate or the office to be given to the guest teacher.
The download is a .zip file with two Word docs inside. You might need at least a bit of knowledge about how to modify tables to make this work best for you. (Or, a nice friend with the knowledge who can help tweak this for your schedule.) The modification only needs to be done once a year. I left my information in so you can get an idea of what types of things I typed in. Anything that is a daily or weekly routine can be put in ahead of time.
Hopefully these documents will work as well for you as they have been for me. Happy planning! :-)