No time line. Just start sowing. If you need seeds, email me and post on my newbie thread.

Just remember hardy annuals and perennials when there is lots of snow or frost, then when things warm up half hardies and tenders.

i find these lists very helpful. the whole site is amazing!

Here is a link that might be useful: WS seed lists

Sort your seeds and plant:
First (soon): any that are perennial in your zone
Next (when you are done with above): hardy annuals
Next: (when it's starting to warm up - around here April): annuals