Below are the most popular venues for kitesurfing / buggying / mountainboarding in the South east of UK.

Allgoodfun Kitesurf Group
Want to join in on a group of people that are out throughout the year - doing demo's, instuction, and generally having fun. Click here to see what we are upto

Camber Sands / Gurys Gap: Fantastic location on the south coast of the UK, thats great for kitesurfing, buggying and mountainboarding, Ideal for WSW, SW, S, SE, ESE wind directions for kitesurfing. This beach has groynes, and is not useable at high tides, and is mainly sand, except for a pebble area at the
top of the beach
Please Note that you actually kitesurf from Gurys gap, and most kiters park at the Broomhill sands car park.
Most local weather station (lydd Airport) - add 7mph to windspeed approx 

Greatstone / Littlestone: Great location for Kitesurfing, Mountainboarding and buggying. Here the tide goes out a long way at low tide, and i mean a long way, This beach has no groynes, and can be ridden at all states of the tide (but advise against riding at high tide), there is about a 100mtr strip of sand that runs almost the whole length of the beach, which can be used for mountainboards and buggys, further out it gets muddy!. Ideal for NE, E, SE wind directions for Kitesurfing. Local weather station, Lydd airport

Minster, Isle of Sheppey: Good location and can be used at all states of the tide, and at top of beach its pebbly, and then going to sand, then patches of mud (not too bad though). Good location at low tide for beginners, Ideal for NW, N, NE, E and is in NW, N winds fairly flat. Easy access payable carparking on
beach. Local weather station

Tankerton: Ok location for kitesurfing only, but has sharp stone and shingle area, and some muscle beds (these eat kites!), Ideal for W, NW, N, NE wind directions for kitesurfing, as you can walk out to point, and kitesurf from there, but can be rough at times, and with a NE wind means there is a flat area, just beside
the point.

Whitstable: Ok location for kitesurfing only, but has sharp stone, sand and shingle area, Ideal for W, NW, N, NE wind directions for kitesurfing, but can be rough at times (High N, NE winds), but smooth in (W and E), and has shingle strip to far right hand side.

Minnis Bay: Good location to kitesurf, with majority of beach is sand, but there are sections that have sharp stones, This beach has long Concrete Groynes, and high tide is a definate no, ideally avoid up to about 2 hours
either side of high tide to give plenty of room, there is a specific kitesurf zone o look at signs. Ideal for NW, N, NE wind directions for Kitesurfing. Local Weather report

Below are some useful weather and tide links:

Met Office: This covers the inshore weather for all of England, for North Kent coast its generally 'The Wash to
North Foreland', and for Camber sands/Gurys gap/Greatsone its 'North Foreland to Selsey Bill' 

XCWeather: A very good easy to use weather forecast, and can be animated.

Windguru: A fanstatic weather website that can have your own settings set up (once you have registered - Free)

New Romney Weather: A Very informative weather report for Greatsone/ Littlestone.

South East Tides: Good for checking the tides out locally - For:
Camber use Dungeness
Minster use Sheerness
Whitstable Use Whitstable approaches
Minnis Bay Use Margate

Windrfinder: World wide weather

Tides: by the BBC - by the Admiralty - Clickable map
National Data Buoy Centre - Readings
Cornish Web Cams
Cornish - Newquay & Perranporth spot info with forecasts
Cornish - FistralCam - has current and forecast weather
Windwatcher.net - Current conditions around the UK & surf spot info !
Weather bouys around the UK - Current Marine Conditions around the UK
Poole Harbour - speed, direction and other weather info
Chichester - speed, direction and sea state
Worthing - web cam and wind details and sea state
Sheerness - web cam and weather details
Shoreham - with last 50 minutes detail.
Hastings (Camber Sands) - with archive ...