I agree, sow some of them in pots now and some in the spring. If you have a cold frame, overwinter the ones you sow now in there, and they should flower next year. Those sown in spring will usually not flower until the year after.
Bear in mind that they don't come true from seed, but you can select the best ones when they flower and pull-up those with non-descript flowers or colours you don't like (which, in my experience, is usually about 3/4 of them.) I find it quite exciting when it comes to seeing what the first flowers will be like - there's always a surprise, if you sow a lot of them!