The best way to install solar is through a qualified professional who holds a certification to do so and works with high-quality solar panels. The industry-standard certification is awarded through the North American Board of Certified Energy Practitioners (NABCEP).
For example, 100Ah at 12V equals 1. Converting amp-hours to kilowatt-hours is straightforward once you understand the formula and why each component matters. Multiply amp-hours by voltage to get watt-hours, then divide by 1000 to convert to kilowatt-hours.