For a succinct introduction to bases in Banach spaces, Christopher Heil has provided A Basis Theory Primer. (The first 20 pages are a quick review of Banach space theory. The rest is devoted to bases in Banach spaces.)

For a succinct introduction to bases in Banach spaces, Christopher Heil has provided A Basis Theory Primer. (The first 20 pages are a quick review of Banach space theory. The rest is devoted to bases in Banach spaces.)