Going to reprint something I wrote to another poster the other day:
I recommend to every new player I meet that their first mech purchase should be a Hunchback 4SP. It is economical, and relatively cheap and simple to upgrade into a quick and powerful medium brawler. All you have to do to it is:
1. Upgrade to double heatsinks
2. Upgrade to endo-steel structure
3. Upgrade the engine to a 250 standard
4. Replace the head small laser with a 5th medium laser
5. Add heat sinks or ammo to taste
Here's a sample:
http://mwo.smurfy-ne...7a720fab4f86d10
This is a pretty nimble and durable loadout with stopping power where you will still have half your weapons if you lose one side, and still have a laser if you lose both. Great for learning how to aim with beams, and slow projectiles (the SRMs). Also will teach you heat management and firing groups. If you have a four button mouse, I suggest a left lasers group, a right lasers group, a SRM group, and a head laser group, for optimal heat and fire control.
I normally discourage people from going light first, just because it is more difficult to learn fundamentals when moving at high speed (which you should always be doing in a light), and their fragility discourages some new players.
On the flip side, I'd also discourage going assault (or even heavy) until you have a feel for how things work, else you are hurting your team by taking up a powerful high-tonnage slot with your learner's permit.
Medium is a great weight class to learn to play in, when you consider your next purchase.