It's about time to pull supplies together to plant sweet pea vines. Renee's Garden Seeds (click here) has fully illustrated instructions on planting sweet pea seeds indoors for transplanting outside early to mid-April.
Our zone 6b last frost date is April 15th so sweet pea seeds would be planted indoors the first of March if you use Renee's guidelines.
Renee suggests that instead of soaking those large seeds with thick out coating, you use a nail clipper to nick them. Take a look at the photos at the link to see how it is done.