As I understand it, in Kingdoms one progresses from small to epic battles. Any rough guidelines as to how many points that would be per side? Is it 1500 in turn 1 and 4000 in turn 10 or something along those lines? I.e. will one be able to field 2 dragons at the end?

Actually, let me give a more complete answer (I was rushed for time earlier).
The campaign system, as written, has 3 rounds at 1,500 points, 4 rounds at 2,000 points, and 3 rounds at 2,500 points. These are "base" points only. Some scenarios will give fewer or more points to one side or the other, e.g. a "Last Stand" scenario will feature a smaller force trying to hold out against a larger force and getting victory points for each turn it holds out.
Now, if you want larger battles, the good news is that I calculated every number on every card using a percentage. So let's say you would rather go 1,500, then 2,500, then 5,000. The 1,500 and 2,500 values are already printed on the card. To get the 5,000 values, you'd just double the numbers associated with the 2,500 column. You'd get twice as many points, twice as many command actions, and you'd need twice as many points to get the same level of victory on the victory point chart. Completely straightforward. Using the existing values, you can get 1,500, 2,000, 2,500, 3,000, 4,000, and 5,000 with almost no effort-- just using the printed values, or else doubling the printed values. If you are handy with a calculator, in less than 3 minutes you could calculate arbitray point values for any scenario you choose-- just multiply the values by something other than "2".
As for the other question, about getting 2 dragons at the end-- even just using the campaign rules as published, this is possible for 2,000 and 2,500 point battles. You could even field 3 dragons, if you purchased the appropriate Kingdom resource for you Kingdom, which allows you to field 1 extra of each type of elite unit. They'd be awfully expensive, though. :-)