Picking what fits you
If reading isn't your thing, use the audio manual. DMV has it in English and Spanish, and you can listen on the bus or while you walk.
If English is your second language, the test itself is offered in eight languages, but the manual is only in English and Spanish. Read the Spanish manual if it's easier, and take the test in the language you're strongest in.
If you're a teen, driver education is optional for the permit, but it changes what comes after. With an approved course you log 50 practice hours instead of 100, and if you passed the course in the past two years DMV can waive your drive test. ODOT lists approved providers by region.
Practice apps help most at the end, when you've read the manual and want to drill. Check when an app was last updated, because a stale app can teach old rules.