Advice for First Build , Budget around 700-800

Approximate Purchase Date: maybe in about 2 months

Budget Range: 700-800 after shipping

Buying a monutor: Yes

System Usage from Most to Least Important: gaming , watching movies, schoolwork but mostly GAMING
Are you buying a monitor: Yes / No


Do you need to buy OS: Yes

Preferred Website(s) for Parts: newegg.com or amazon.com

Location: United States, california, San francisco

Parts Preferences: I would like to upgrade to Intel CPU)

Overclocking: what exactly is this?? (maybe)

SLI or Crossfire: what exactly is this ?? i would say NO