• ACloudGuru ($35/month w. trial)
• Adrian Cantrill ($80)
• AWS Readiness (4h) ($0)
• Neal Davis ($10-80, ~$15)
• Stephane Maarek ($10-125, ~$15)
• Whizlabs ($19.95, whole site sub $99/year)
• Zeal Vora ($34.99)

I only have experience with last 3 courses and the free readiness course. For me both Maarek and Whizlabs courses are good, but lack depth. Vora's course are detailed but maybe a little tedious, it has a lot of hands-ons that fill the gap left by other courses. Would I recommend them? Yes, I do, they are well worth the money, which isn't much compared with the exam registration fee.

• Bonso/TutorialDojo 4 tests (varies, ~$15, wait for sales)
• Braincert 7 tests ($30)
• Davis 6 tests (varies, ~15)
• Maarek 1 test (varies, ~15)
• Whizlabs 6 tests ($15.95)

Doing practice exams is essential. All practice exams have typos, errors and bad explanation, but they still help greatly. Just pick one or 2 from above. Do an exam in one 3-hour setting at least a few times.

• youtube "how I passed..."
• reddit "passed architect..."
• Just google "how I passed aws solution architect professional"
• tutorialsdojo study path
• tutorialsdojo cheatsheets
• AWS developer guides and API references
• AWS whitepapers
• google "(service name) faqs" for unfamiliar services, for example, "global accelerator faqs"

Focus on courses and practice exams first. Read FAQ's to get overall pictures of specific services quickly. Read developer guides and whitepapers to go deep into a specific topic. Explore other resources if you have time.

1. pick a exam date and register for the exam
2. come up with a study plan
3. stick to the plan
4. (optional) do lots of hands-ons during study

My notes.