Saving seed is a great way to raise new plants in the spring, but some seed is easier to find and save. On the left, Calendula, the English Marigold delightfully unattractive to slugs and as such very different to the popular, but ever eaten, French Marigold. If you have one Calendula, you will have a lifetimes supply. The seed is quite large and easy to handle; it dries well and sows reliably. Viola seed is also quite easy, although much tricker to handle, you need to wait until the flower dies back creating the seed pod and just as it opens and ripens, harvest the seed. Rocket seed is easy as it runs to seed so easily.
But other seeds are rarer or more tricky and if you can't find what you want in the local garden centre, subscribing to the RHS seed scheme is a good source of buying unsual seed and easy time spent over the winter reading through the catalogue and looking up some of the less well know varieties and choosing some seeds for the spring. You need to be a member of the RHS but its a great organisation, free entry to some gardens, the seed scheme, members advice area on the web site, and the monthly magazine is a gardening Magazine to beat all gardening mags.