Question
How do you know the seeds are ripe?  Also would I plant the seeds now or wait till spring to plant?

Answer
The seeds are ripe when the pods turn brown and the seeds inside of them are dark.  Mother Nature would plant them as soon as they are ripe so why not you?  If you are concerned about remembering to collect the seeds before they fall, take a piece of netting (nylon stocking works well) and fasten it around the seed pods with a clothespin or a paper clip.