If I were starting from scratch, like you seem to be, I would follow the grass care and maintenace plan by Jerry Baker. He uses alot of common ingredients that may sound off the wall, but he apparently gets good results. I bought one of his books and was going to try his technique but my husband thought I was crazy and called the local lawn service. I hate the idea of chemicals on my grass!!!

I've attached a link to Baker's web site.
http://www.jerrybaker.com/index.asp?PageAction=Custom&ID=78

I would be interested in hearing from other listers who have tried some of Jerry Baker's methods!

I sounds like, you have drainage problem.
There are two choices: Fix it or live with it. To fix it, you may need a professional landscaper or a contractor come and look at it. It could be that you have a bad grading on your land. This could be solved by grading; putting soil at the low spots and making slope away from house towards the back of your property or wherever it can drain away. If that is not possible, they can dig a french drain. Your second option would be to put a raised bed and plant water loving plants like irises.

Since you're starting from scratch, you have some interesting possibilities for your landscaping if you work in harmony with the natural tendencies of your yard. With some creative planning, you could create an attractive landscape composition that uses three elements:

1. A traditional green lawn area
2. A mini-meadow area
3. A beautiful meditative bog garden

1. TRADITIONAL LAWN: For the traditional green lawn area, try GardenWeb's Lawn Care Forum and Organic Lawn Care Forum.

2. MINI-MEADOW: Think romantic "country meadow" instead of "unkempt weed area". You could save yourself a lot of work and money by creating a "mini-meadow" area in your yard.
Your new "mini-meadow" could then taper into a nice border constructed with bricks, stones, or a hedge, which would border your traditional lawn area. See GardenWeb's GardenWeb Meadows & Prairies Forum for more info.

3. BOG GARDEN: Think "bog garden" rather than "swamp". Rather than fighting against the poor drainage in your yard, and installing a costly drainage system, you could instead enhance the natural wet area by creating a beautiful bog garden full of iris, ferns, turtlehead, etc., and even a mini-pond, or fountain. GardenWeb has a whole forum for "Bog Gardens" (see link below).

Here is a link that might be useful: GardenWeb: Bog Gardens

If you plant Iris, try Japanese iris. They like moister conditions than some of the others.

Siberian irises like to have their feet wet, too.