I cycled from Barra to Stornoway in August 2006 and had a fantastic trip, so I thought I'd recommend a few places to camp and a few pubs etc. I did the trip in two weeks, so it was a very chilled out pace. It was good to have this time though, as it gave me plenty of chance to get a taste of the place and mix with people.
I got the ferry from Oban and camped just past Garrygall, about a mile or so down the road from Casblebay on the first night. It was a nice spot on long grass which made for a comfortable bed. Try to cycle over to Vatersay, it's such a peaceful place.
I think generally Barra, Vatersay and Eriskay were the highlights of my trip. The landscape is amazing and the locas are exceptionally friendly and hospitable. There's an excellent camping spot on Eriskay just down the road from Am Polotition - well worth staying there.
Next night I stayed in a characterful bunkhouse in Howmore. Oh, try and familiarise youself with the Gaelic names as well as the English because you might find yourself stuck otherwise!
Uist is relativley flat, so you can get a fair distance covered in a reasonable time. There are a couple of shops and pubs along the way, but not too many so make sure you have at least 2 days worth of food with you all the time.
The lochs through Benbecula and Lochmaddy are quite surreal! I suffered a massive midgi attack in Lochmaddy - so not the most fond memories!
Harris. There is an excellent bunkhouse in Leverburgh ! I mean really good, nice new timber building with an open fire and excellent facilities. It was such a welcome break from camping rough all week. Rodel Church is worth a visit.
Quite a demanding cycle from Leverburgh to Tarbet. I like Tarbet, nice to see a few faces once in a while. The youth hostel is ok...and the pub is quite good. (at some points on these trips anything with a roof is good!).
A difficult cycle again from Tarbet up through North Harris, but a fantastic setting.
There is a pub somewhere on the A859 near Loch Erisort that is OPEN ON SUNDAYS!!! They let you camp in their garden, and you can have breakfast in the morning.
Calainis standing stones, worth a see. East Loch Roag, spectacular. The black house bunkhouse (something like that) is definatly worth a stay. Old stone bunkhouses with open fires and lots of character.
Then I went to Stornaway which has a couple of good pubs and good art gallery, and back on the ferry over to Ullapool where I got the bike bus to Inverness.
It was such a fantastic trip, so peaceful and rewarding. I'm going to spend another two weeks over there cycling this year I think.
Have fun,