NSURL *url = [NSURL URLWithString:@"targetサイトURL"];
NSURLRequest *req = [NSURLRequest requestWithURL:url];
[webView loadRequest:req];

参考

• http://akabeko.me/blog/2014/01/ios-uiwebview/
• http://hagino3000.blogspot.jp/2013/12/ios-webview-vgadvent2013.html
• http://kouji1981.hatenablog.com/entry/20111009/1318141565