Growing from Seed

I really suck at growing things from seed. I have tried the past 2 years and never got anything to survive long enough to go into the garden. I had decided not to try it again, however, I still need to add plants to the garden (my thinking is plant in the front and plan in the back) so I am ordering some seeds from Johnny's. I have learnt that I should by from somewhere with a similar climate, that are grown and tested there and to plant in a soiless medium. Hopefully this will help my success rate.
The decision to try again was motivated by my move into a new office at work (pic). It has a lovely large window and wide window sill and I was thinking the other day where I could put seed trays at home when it hit me - the office window is the perfect place. So I will throw down $100 or so and await arrival.
Although the pic looks somewhat arctic, the snow has actually all melted in the past week.