Hi Jimp!
10 years ago I was an LM virgin - now I'm retired and live here! Our first trip was with a well-known UK-LM travel operator, by overnight coach, and the journey was hell - virtually sleepless in both directions. But the race was wonderful, so we persevered.
One piece of advice? If you want to see the easy-walking parts of the circuit, roughly from Maison Blanche to Tertre Rouge, and I'd strongly advise it, then make sure if the weather is at all hot, you have access to plenty of water. I've seriously regretted not being hydrated more than once around there!