I'm wondering if it's at all possible to upgrade my CPU and maaaaybe my GPU, too. If so, how far can I upgrade it? I know sometimes you can only go up to a certain point before you need a whole new motherboard. If you'd like to, you could give me the same information for my RAM and motherboard, just in case I want to go all out at some point (though in that case, I should probably buy a whole new computer... maybe next time I'll go with a desktop instead >_> they're a better bang-for-buck).

These are my laptop specs, I have a HP Pavilion dv6700 CTO Entertainment Notebook PC.

Operating System
MS Windows 7 Ultimate 32-bit SP1

CPU
Intel Mobile Core 2 Duo T5550 @ 1.83GHz
Merom 65nm Technology

RAM
3.00 GB Dual-Channel DDR2 @ 332MHz (5-5-5-15)

Motherboard
Quanta 30D2 (U2E1)

Graphics
Generic PnP Monitor (1280x800@60Hz)
256MB GeForce 8400M GS (HP)

Hard Drive
59GB Patriot Torqx TRB 64GB SSD ATA Device (SATA-SSD)

Isn't this a laptop? In that case, I'd rather not try to upgrade, and it won't be a huge difference anyway.

I'm afraid that's the sacrifice you make when opting for a laptop.
You gain portability and lose upgradeability. Some laptops are able to have their CPUs changed without an electrical engineering degree. Others have daughterboards with the GPU on them that can be changed, but usually for something in the same range of performance, more for servicing/replacing broken components than offering a true upgrade path.