Architecting isn’t a standardized discipline, but some companies, societies and universities offer courses. There are also a number of books that contribute to shaping the profession.
Enterprise architecture
Enterprise architecture is the architecture discipline that develops and documents the entire business to best pursue its mission statement.
The requires business capabilities are often supported (automated) by solutions consisting of one or more applications and business processes.
Solution architecture
Solution architecture is the architecture discipline develops, documents and maintains a solution comprised of (often integrated) applications and business processes that utilize these applications.
Building a solution that’s robust, useful and manageable requires an engineering process that solves technical problems, and enables efficiency and productivity.
Robust means the design will last at least to or past its intended life expectance, and accommodate changes due to shifting requirements and technologies with manageable effort and risk during its life time. Useful means the design provides exactly the necessary functionality needed to execute the dependant processes. Manageable means the design allows for changes with little or no disruption of operations, and that it's observable and can be controlled without interfering with its use.
Efficiency and productivity is best achieved by following an efficient and lean development process in combination with suitable tools.
Some of the books in my reading list focus on solving many of the technical problems than often materialize in the design process.
A key activity in the architecture process is to document the design- it helps capture and convey decisions and pass knowledge from the developers to the maintenance staff. When documenting architecture, use a template that fits your development process and helps you cover all significant aspects of the design.