The Isle of Man is a superb place! I have been there once and my Mum and Dad go there frequently. I am taking the caravan over there this year too which will be a first, although I need to apply for my permit first
It's incredibly diverse with its countrside....think of it as a miniture UK...you have superb coastlines, glens, rivers, lakes, hills, lowlands, coves, beaches....need I go on! Its also very quiet too.
I will say this though, its paradise for walking, mountain biking and other outdoor persuits, but its not the kind of place you can appreciate from a car all the time....you have to use your body to fully experience the islands assets.
When you go on the ferry or seacat, makes sure you ask for a FREE parking permit onboard then you can park in the town centres without having to go to a tourist info centre or supermarket to get one when you arrive.
The Laxey wheel is a good attraction, although it might not be open in March. The same goes for the Victorian Snaefell railway. The Trams (also Victorian that go from Douglas to Ramsey) will be working, so get yourself on those....they are a work of art considering they are still all ORIGINAL!! and they are funny as they are so noisy.
The steam trains may be running I think from Douglas to Port Erin. Ballaglass falls is also a spectacular set of waterfalls worth visiting.
There are lovely towns and villages to look around too, but beware that the only real mainland style entertainment is based in Douglas.
As I say walking is great, so don on your walking boots and do some of the superb coastal walks!
The island is deceptively big.....you really feel as though you are on a much much bigger island.
The truely unique thing I found about it was that nowhere in the world (I think) can you see 4 countries from an island....Scotland, England, Wales and Ireland.
There is an Alfa dealer on the island too and lots of car specialists, so don't worry too much about taking your garage with you
Douglas is a nice town with Marks and Spencer's etc to please the misus
so its a good place to stay at if you want nightlife. If you want to be with people but still not too busy, then Ramsey is good, or Peel.
Glen Maye is a lovely place if you want piece and quiet.
Anyway I hope this has given you some useful info!