Cirrocumulus

They look like rippled sand, an omen of fair weather, sometimes they appear after a storm and dissipate to leave a clear blue sky.  

altitude:  5 - 8 km, (3 - 5 miles)

Altostratus

Fair weather clouds, on a larger scale than cirrocumulus,

a bit thicker and not so white with slight shadows in them, they often appear after a storm and drift around

altitude:  1.5 - 6 km   (1 - 4 miles).

Cumulonimbus

Low forming thunder clouds, often growing and transforming in size fast.

Quite often these towering clouds can look rather Dark and Menacing with the top flattening into an anvil shape. These clouds are the bringers of thunder and lightning, hail and strong wind. False cirrus often appears above them and false nimbostratus below.

altitude:

Can form at 1.5km and rise to a staggering height of 10 km (1-8m)

Cumulus

Easily recognisable fluffy white clouds with flat bottoms, usually indicate fair weather when widely separated, but if they appear quite large they are capable of producing sudden heavy showers. When seen out at sea in an otherwise cloudless sky, they often indicate land beneath.

altitude: 2.5km or less. (2 miles or less)

Cirrus 

High wispy clouds formed from ice crystals which gives them the white appearance, an indicator of fine weather.

altitude: 5 - 9 km (3 - 5.5 miles)

Cirrostratus

Made up of I've particles and look a bit like white veins. These clouds can also produce a halo around the sun or moon.

altitude: above 6km  (4.5 miles)

Altostratus

These clouds form a greyish veil over the sun or moon. if wet weather is approaching the cloud will darken and thicken obscuring the sun or moon until it begins to rain.

altitude: 2.5 - 6 km (1.6 - 3.7 miles)

Nimbostratus

These clouds form low dark blankets, they signal rain or snow within 4-5 hours, the rainfall or snowfall usually lasts several hours.  

altitude: 1.5 - 5 km (1 - 3 miles)

Stratocumulus 

These beautiful clouds form a low lumpy rolling mass, usually covering the whole sky, though often thin enough for the sun to filter through, light showers may precipitate from them, but these clouds usually dissipate in the afternoon, leaving a clear night sky.

altitude:  2.5 km or less (1.6 mile or less)

Stratus

These are the lowest of all clouds and form a uniform layer like high fog, they are often described as hill fog, not a normal rain cloud but they can produce drizzle, when they form quickly overnight and cover the morning with mist, often they clear in the morning sun and lovely sunny day follows on.

altitude: Less than 2.5km (1.6 miles)