njoasis, I am doing the same- after making marmalade from these seeds, I potted some of them up to grow. There was a post recently from a woman entitled something like "Seems like I have given birth" who grew a seed from a Seville orange that she got from Spain and in 10 years was giving blossoms! You could scroll back a few pages to find her post.

the seeds of the fruit will yield flowering plants, but it will take a while (years). You may as well order a grafted plant or one propagated through cuttings to get fruit immediately (my recommendation is a grafted variety). They are very easy to maintain and I have heard that some people use this variety as a rootstock just because of its hardiness. The flowers of this plant are rated as the most fragrant among all citrus.