You ask a great question! While some students can learn GRE quant with just some prep books, I’ve found that my students are more successful when using a more robust resource such as an online self-study course. Self-study courses typically provide detailed study plans and have granular analytics, so you can easily track your progress as you move through the course. The ability to track your progress will keep you more engaged, and you’ll be able to more accurately forecast when you’re ready to take your real GRE.
If you decide to go that route,
GRE Prep Club has verified student reviews of different GRE prep materials.
Also, here is an article I wrote that I think will give you some more valuable information:
How To Score a 330+ on your GRE.
Please reach out with any further questions.
Good luck!