To answer your question about men who became officers, the usual kind of man had a name that people in a particular area recognized. He might be an attorney, a merchant or a public official, such as a court clerk. He might or might not own slaves. These men lived and worked in small towns where people came to trade and do business. Farmers and planters usually lived in remote areas and weren't as well known. For that reason, not as many planters as one might expect became officers.

Volunteers gathered in open places just outside towns rather than in buildings. Buildings were usually occupied for some other purpose, and there were usually convenient points near towns such as a fairgrounds or a militia drill ground where they could assemble. It was usually important for the camp grounds to be near a rail line, main road or navigable river so they could be secure passage to some other point quickly.

Newspapers during that time always contained advertisements placed by officers looking for recruits. They weren't very large or colorful, but would include the recruiter's name, the name of the company, perhaps a line or two about where he expected the company to go (Volunteers for Virginia!) and an address where prospective recruits should report. They also mentioned the term of enlistment, often twelve months.

When there were enough men available to form a company, an election was held for officers. The captain then signed a roll including all the men who had enlisted in his company which reported each one's name, rank, age, birthplace, occupation and residence. When there were not enough men to form a company, two small local commands might merge. Examples were the "Northport Rifles" and the "Tuscaloosa Rifles", which assembled under the name of the latter, since Tuscaloosa was also the name of the county. It was assigned to duty as Company "G", 11th Alabama Infantry Regiment.

The roll usually went to the Governor, who returned a note showing that he had accepted the company in state service. This was important because the officers and men received pay from the date they were accepted in service. The Governor would then direct the company to either remain in camp or report to some other assembly point, such as Corinth MS, Lynchburg VA, or Mobile AL. In either case, the company was usually assigned to a regiment or battalion that included other companies from the same state.

By November 1861 most of the arms that had been seized in state armories such as Mount Vernon AL had been distributed, so the men might carry shotguns or other non-military type weapons, and hope to secure better in the future. Many companies which applied for duty in November 1861 were turned away because arms were unavailable. Home manufacture, captured arms, and weapons imported from Europe began arriving during the next year. Usually other equipment was issued when the company arrived at an assembly point.

I'll let someone else make additoins and corrections....