When (and how) should I start seeds for bonsai?

Question

On a walk through my neighborhood, I noticed that the trees are already dropping seeds, and I picked up several each of:

• Oak (exact species unknown)
• Maple (ditto)
• Japanese maple (ditto)

1. If I wanted to try to start them as bonsai (yes, I know that will take a while), should I get them into soil now, or wait for the fall?

2. I've read all sorts of stuff about soaking seeds in hot water, keeping them in the fridge to simulate winter, etc. How necessary is all that?

Update

This photo illustrates the condition the seeds are in:

Answer 1

I have started bonsai oak and horse chestnut from seed. I collected them in fall, so I don't know how you found them in the middle of summer. Are they from last fall? But if your seed is viable, you can put them in a container with potting soil. Just leave them, keep it a little bit moist during a period of drought, and in spring they will germinate. They need a cold period before they germinate.

I am a bit curious though about the condition of your seeds. When you find them in summer, they might be from last fall and therefore not viable anymore...