The biggest point is to minimise weight on anything that spins. This will make a big difference to acceleration and climbing. For example, I really noticed the difference when I saved 100g from my gear cassette, but didn't notice the extra 500g stuck on my seat after xmas.
Folding tyres are normally 50-100g lighter for the same tyre model, so well worth getting, which ever tyre you prefer. The wired Kendas are about 340g, the folding version is closer to 260g. Some tyres are heavier and have more p*ncture proofing, so tyres are a bit personal depending on their expected use. Check out a tyre thread for some other peoples opinions and make an educated decision based on that.
Same goes for the wheels. A touring wheel will often be heavier and stronger with more spokes than a commuter wheel, which is in turn heavier than a training or race wheel. Lighter doesn't always mean more expensive either, but there are diminishing returns on your cash to shave those last possible bits of rotational weight, so the lightest are a lot more than middle weight generally.