Hey Bane, good to see people still getting into the hobby! This forum unfortunately seems to be dead, but I'd redirect you to
The One Ring if you haven't already found it. Alternatively
The Last Alliance. These are the main two LotR forums I am aware of.
I collect Gondorians and Goblins myself, with a smattering of other factions thrown in. This is for the Strategy Battle Game as opposed to War of the Ring which takes a lot of models to get started. I do recommend getting two opposing armies if possible so you can invite someone to play the other or just battle yourself (or if you're a collected/hobbyist rather than gamer, just get the ones you like). The game can work well from just a couple of models a side. There was a White Dwarf supplement that came out ages ago called Battle Companies that had about 7 a side initially and expanded in a typical roleplay fashion. Sites like TLA or TOR listed above have updated rules members have invented for them.
Between Gondor and Dwarves? Well both are heavily armoured. Gondor tends to be more of your average man stat line though. Good at everything, great at nothing for the common troops, though they'll beat your average Orc. They have quite a number of specialists though who fulfil different roles and some really strong heroes. Dwarves tend to be slow and defensive. With less movement and bodies than other races, they tend to stick together for support. While Gondor will generally form a flexible shield wall with quite a few bodies and maybe some cavalry and archers, Dwarves will form a solid rock around which they have some rather strong elites such as Khazad Guard or Iron Guard which do the main damage.