How can I figure out why my internet is so slow?

I have cable internet and I think it’s 3MB transfer speed?(does that make sense?)

I have a wireless router which my phone and imac use to connect to the internet. Lately my mac has been disconnecting a lot and I have to unplug the modem and wireless in order to get the signal back(usually just unplugging the wireless router will work).

I opened network utility but really don’t know much about it, it was saying:
sent packets: 29k
recv packets: 24k
(both of those constantly change but were staying around those numbers
link speed:54Mbit/s

What can I do to figure out where the slowness is coming from and to stop the disconnect problem?

I have a Belkin wireless router…my guess is a cheap router=poor connection.

Also it’s password protected so I really don’t think anyone else is on it…