10 mbps (1.2 MB/sec) should be fast enough for most things people will do on the Internet. Can you try turning off a device's wifi and plugging it directly into your router via an ethernet cable? That eliminates the wifi network as a possible culprit. Test the Internet speed that way. Try speedtest.net to make sure you're getting the service your ISP says its selling you. If it's fast enough for your needs, then the problem is probably the wifi, not your Internet connection.
If you think your wifi is the problem:
Check to make sure you're broadcasting on a clear channel. For North America, you can manually set the channel to 1-11, though in reality only 1, 6, and 11 don't interfere with each other. Check with a wifi net management app or your smartphone for what channels your neighbors' nets sit on. Then set your router to a different channel. If the router has an auto channel function, use it. If all three channels are occupied, pick whichever one has the weakest signal.
Another gotcha is that most routers will default to the speed of your slowest device. So if you've got a 802.11n router and 3 n devices, but also an old 802.11b device, your router will fall back to 802.11b and the best you'll get from any of your devices is b speeds. If you suspect this is happening, you can try shutting off all the devices, rebooting the router, then turning on your newest device to see if that improves the speed.
Another reason this can happen is if a neighbor is leeching Internet off of you. Because the neighbor is further away, the router will slow down its transmit speed to maintain the connection. But when it does this, it again slows down its speed for all devices. If you don't have security enabled on your wifi network (WAP2, WAP, or WEP in decreasing order of preference), enable it. If you do have it enabled, try changing the password.
Microwave ovens operate at approx 2.2 GHz. But they are powerful enough that they'll pretty much swamp out a 2.4 GHz wifi signal. So if you or a neighbor is using a microwave oven a lot, this will also degrade your wifi connection.
For reference, 802.11n will give you about 11 MB/s in real-world use (22 for some implementations), 802.11g about 5 MB/s, and 802.11b about 1 MB/s. So in most cases your wifi network will be much faster than your Internet speeds. So make sure you test plugged in with an ethernet cable first.