A lot of good advice already and a lot comes down to budget for both the bike and insurance as a new rider along with the cost of some decent kit to wear while riding I guess but here goes my thoughts.
Personally, unless you want to tinker I would go for an injected bike- as Dirty says there is certainly nothing wrong with carbs (I have run a 1997 900 for what will be a very happy seventeen years at the end of this one) but you can't escape the fact that the carb'd models (along with the early injection bikes) are getting on a bit in years and as such many items like fuel lines and vacuum pumps etc. will either need or soon need replacing.
Also if you have to put the older bikes into a shop (either main dealer or specialist Ducati) the service/work costs to bike value ratio can be very steep.
But on the flip side if you are confident and like playing with spanners the bikes are cheapish (depending upon model) and it is a great way of 'bonding' and getting to know your bike....gotta love 'date night' in the garage
So if I were in the market for a new bike (which I kind of am actually, to go along side my '97 Monster) and wanted a Monster (which I kind of do too) I would (am) be looking at a 696 as a jump on and go anywhere bike- if you prefer the look of a single sided swing arm then there is it's big brother 796 instead.
Servicing is on the cheap side of Ducati ownership as are insurance costs due to them not being the scumbags choice for an angle grinder attack!
As already said, if looked after they start on the button, are fun to ride and quick enough on real life roads and ooze Ducati style and coolness.
In addition, should you decide it's not for you or you want a few more cc's, as with most Ducatis once values plateau you won't lose too much (if any) if cared for.
Look at condition and history rather than mileage (Ducati's like to be used) and don't be put off by the colour as the body work is designed to be easily changed.
