The Renaissance, meaning 're-birth of classical antiquity', was centered in Florence, the capital of Tuscany before Italy was unified. It was fostered by scholars who studied at the recently opened University of Florence, which gave a secular (non-religious) education, especially no longer connected to classical Gods. The course was known as the 'Studia Humanitatis', and when qualified the students were known as 'humanists'. Such a humanist would be fluent in Cicero Latin, and later in the 15th Century, Greek.
The principle subjects were Grammar, Rhetoric, Latin, Mathematics, Geometry, Music and Poetry - with these they would debate philosophically, and quote classical authors in which they were well versed. Most of the students became speech-authors and politicians, and therefore wielded great power in society, which was very important in the development of Renaissance art and architecture. They were classical bibliophiles, which was a huge change from the Gothic era which was centered on fear, faith and the power of the Church.
The Renaissance essentially happened in Florence due to three main reasons; the University, Industry of Trade and Textiles, and Banking. Whilst the humanists were philosophical, the people of Florence were generally quite earth-bound, pragmatic, practical people which led to a huge increase in documentation. Many became quite wealthy and invested their money in education for children, especially as humanists could then tutor them, and they invested in art. However, it was not directly the humanists that set off the Renaissance, but indirectly through art commissions, political influence and emulating the classicists.
The city prospered through trade of textiles particularly, and made a lot of money internationally. Wool was actually imported from Norfolk, silk and dyes from the East, as far out as Afghanistan, with which they made beautiful textiles. This trade encouraged the formation of Guilds, mostly for cloth-importers and bankers. The guilds themselves commissioned heavily and therefore supported this great artistic flourishing.