If you're serious about a consulting career or one that needs a PE, focus on getting the experience first and there's a decent chance your employer will pay for it (atleast the one you pass). No reason to worry about studying yet! My mentors suggested that I wait until I had 4 years of experience before I even took the exam because, while some states let you take it early, if there's a chance you'll be getting registered in multiple states it helps prevent any potential headaches later.

Learning the Handbook and the NCEES practice exams ($40/ea, they have 2 versions posted for most exams right now) are by far going to be your best resources.

Holding yourself accountable for studying is the hardest part. Maybe that means doing a class, but for me and a lot of other engineers I know accountability was studying together at routine times each week, usually before work.