7611Kbs is roughly 7mbs though that doesn't mean you will get 7mbs, my router connects at 8mbs but I normally get between 5-6mbs
Go to the below link and do a speed test
http://www.speedtest.net
The difference in speed between first visiting a page and then being faster the next time is due to caching. Take for example this site, when you first come to this site the entire page has to be downloaded from the internet but when you then go to another page certain parts of the page are the same (like the AB logo at the top) so rather than downloading the logo again your computer just uses the copy of it that has already been downloaded.