Bike tour in of the southwest uk

Something like the West Country way sounds like a good idea. My top tip for route planning would be avoid A roads if you can. Oh and don't drink too much 'scrumpy' and avoid 'snakebite'.

add to your kit list cycling mitts. Don't use a rucksack to carry your stuff - your back will hurt by the end of the day and get really sweaty. Borrow a pannier or put stuff in a waterproof drybag and bungee it to pannier rack.
Sustrans website www.sustrans.org will show you UK National Cycle Network but the mapping is frustrating. www.opencyclemap.org is better, but it's open source so comes with health-warning over accurary. I've ridden along roads which aren't on opencyclemap.
Like previous post said, stay off A-roads (& obviously motorways!), they're no fun.
From Sherbourne you could head north to Bristol/Bath. Plenty of tourist stuff in Bath, Bristol is laid-back city. Two fairly easy days would get you there. Over Somerset levels (Glastonbury/Wells) for a bit of flat land so you feel at home.
Or could go west Quantocks/Exmoor/Dartmoor if you like hills.
Afraid I don't know anything useful about hostels.

If you are looking to stay in youth hostels, http://www.yha.org.uk/ is a good place to start. They provide a fairly good standard of accommodation - you generally share a room, with your own bed, bedding provided, towel hire available and shared facilities. There is normally a communal kitchen where you can cook for yourself- sometimes there are restaurants in the larger hostels. Often there is also a supply of communal food or at least basic things like sugar, spreads and conserves.

There are also a number of independent hostels in the UK, which can be found here: http://www.independenthostelguide.co.uk/ I recently stayed in Caerhafod Lodge, Pembrokeshire which was very good and in a fantastic location with a sea view. Hostels are generally reasonably priced from about £10-20 per night. One of the best things about staying in a hostel is meeting other like-minded adventurers.

If you have a bit more money to spare you could consider B&B'ing - these are usually £25-35 upwards and provide more hotel-like accommodation, but are run by local people. To find these just search for "bed and breakfast near x". You should get a room to yourself, although if you are travelling alone there may be a supplement. Facilities may be shared but the number of guests is usually smaller than in a hostel. You can expect a large traditional English breakfast to start the day, and sometimes an option of supper the night before, though you could always try a local pub.

Cycling on roads in the UK I would imagine is pretty similar to riding in the USA. The main differences are that it's on the other side of the road, and that there are many more roundabouts! I don't know how well maintained the roads will be compared with those in Florida. Generally, A and B roads are well surfaced, but unclassified roads vary and you would be doing well not to find a few potholes to avoid.

Best of luck with the trip, wherever you decide to go.

<http://www.sustransshop.co.uk/products/5049-ncn-the-west-country-way&gt; for the map you want.
history major - but you've already been to Roman baths in Bath? Salisbury has lots of old buildings, Stonehenge is a bit underwhelming IMO (overun with tourists) but the surrounding area is full of pre-Roman stuff. Avebury has a large stone circle - pretty impressive.
I find road atlas is only good for planning - generally the scale isn't good enough for navigation. You can look at maps in most public libraries - if you have time/desire to routeplan once you're here. OS Landranger 1:50,000 scale maps are detailed - but you'll probably cross a map a day so buying lots might get costly. If using these then stick to unclassified roads (yellow & white) and you'll be sure they're quiet. (1:25,000 are probably too detailed for cycle touring - show field boundaries etc). <http://www.goldeneyemaps.com/cycle.php&gt; are 1:100,000 but don't cover all of the area you want. <http://www.sustransshop.co.uk/by/category/1-maps--books&gt; do maps of particular long distance cycle paths which are generally all on quiet roads.
Sorry for length - I could write stacks about this but would get a bit dull.......