Does anyone have any suggestions on a good place to stay at La Digue? Are there any particular things one must remember when going there? How much does it cost to get to the island?

don't remember about how much it costs but the cheapest way is to go by cargo boat from mahe straight to la digue.. we did exactly that way and sea was very rough for several times i even thought we're not gonna make it... but it was cheap and adventure for no extra cost :D
flycatchers lodge was around average price and the people were very warm and welcome. next year we're staying there as well. we just loved that place and i think it's the closest place to stay to Anse Source D'Argent and other beaches on the opposite side of the island.
definetely rent a bicycle and go around the island

I totally agree on Paradise Flycatchers. By coincidence I added a few pics and tips on it yesterday on my page. I was there in Sep 05, but I'm only starting to build my pages now.
I believe there are new places since then, but I'd stay there again.
And yes, definetelly a bike. Take a light if you ride at night as there is seldom a street lamp.

At the time we travelled on the regular ferries from Praslin.
And from Praslin to Mahe on the Cat Cocos catamaran. Rough sea, we all got sick. If I ever get back, IŽll take a plane!
As my time was short to search the net, I booked all via www.seychelles-resa.com.
They made me good arrangements for a reasonable price. These people are located in France but will accept bookings from anywhere.

La Digue is just lovely.
Have a meal at Le Patatran Village. The food is excellent and not expensive.
We also tryed Chez Marston and Zerof, which also serve good creole food.