Bruce the one thing I would suggest is to pick your subject based mostly on what you are interested in. If you really like German subjects, then go for a good German kit. If you go for British, as I do, then something British. If you go across type and pick something you're not that interested in just because somebody recommended it then you'll probably lose interest. For my money Tamiya is the class act, and you'll probably not go wrong with one.
As to scale there are basically four main scales. From smallest to largest they are 1/700, 1/600, 1/400 and 1/350. Each has pros and cons. 1/700 is probably the most common, and most of them are waterline. You can get just about every Japanese ship that ever sailed in 1/700, and a good number of other nationalities. 1/600 is an older scale and mostly the kits are old Airfix kits, which are quite old, but buildable. If you like British ships 1/600 may be your best bet. The 1/600 kits I'm familiar with though are full hull. 1/400 is much more common in European kits. Finally 1/350 is the largest, so if you're not used to working with very small parts might be your best bet. The problem with the two smaller scales being that they are harder to work with. The two larger scales cost more, and take up a lot of space on the work bench.
There is also a lot of debate between waterline and full hull. Again 1/700 are mainly waterline. Personally unless you're going to put the ship in a water base I prefer full hull. Most of the larger ships are either full hull, or have the option of going either way. I like the large ships full hull as they look more like museum kits to me. That said I've gotten more positive response from my wife and kids the two waterline kits I've made on water bases.