Olá, segui todos os passos porém a foto do João da Silva não sobe, segue o código.
body { font-family: "Crimson Text", "Times New Roman", serif; background-color: #F2FFFC; font-size: 120%; line-height: 1.5; }
h1, h2 { font-family: "Open Sans Condensed", "Arial", sans-serif; }
main h1 { text-align: center; background-color: #851944; color: #FFF; padding: 25px; border-bottom: 10px solid black; font-size: 60px; text-transform: uppercase; }
p { text-align: justify; margin: 20px 0; }
blockquote { background-color: #D9E5E3; border: 10px solid #C2CCCA; width: 250px; box-sizing: border-box; margin: 20px 40px; }
aside { background-color: #3C1D3D; color: #F2FFFC; }
footer { background-color: #000; color: #F2FFFC; }
nav a { color: #F2FFFC; text-transform: lowercase; }
main a { color: #851944; }
aside a { color: inherit; font-family: "Open Sans Condensed", sans-serif; }
blockquote, aside, footer { padding: 20px; }
main div { width: 720px; margin: auto; padding: 30px 0; }
aside { text-align: center; clear: right; }
aside h1 { font-size: 30px; margin-bottom: 25px; }
strong { font-weight: bold; }
em { font-style: italic; }
h2 { font-size: 30px; clear:both; }
.icones-sociais a { width: 40px; height: 40px; display: inline-block; text-indent: -99999px; }
.github { background-image: url(github.png); }
.twitter { background-image: url(twitter.png); }
.linkedin { background-image: url(linkedin.png); }
.fiat { float: right; }
.petrobras { float: left; }
main { float: left; width: 85%; }
aside { float: right; width: 15%; box-sizing: border-box; }
footer{ clear: both; }
.foto-joao{ float: right; }