Obviously, it depends on how much space and how many pants are to be covered. It is usually my rule of thumb to use approximately 1000-1500 lumens per sq foot for seedlings. Some people use watts per sq foot to assess light intensity. Generally, I find 20-30 watts per sq foot is sufficient for most vegetable plant seedlings for approximately the first month of life. As the plants get larger/mature the light intensity must be increased to keep the plant photosynthesizing at an efficient rate. The 6700 K is the correct temperature for seedling growth. The 25 watt fluorescent will help in that it will add more light and if it is not mounted to anything permanently you can move it to light the darker areas of your garden that may be shaded.

so my cf will cover about 3 by 3 foot area right? even though i won't be using that much space up, i'll prob. put it in an unused room in the house.
what's the diff/. between warm and cool bulbs?

but this will be enough light to start some full sun and partial shade perennials and annuals till mid April right?