You should have a professional installer in your area take a look at your home so you can discuss what end result you are wanting. You may need to use an engineered wood. This is still an all wood product and is much more dimensionally stable than solid wood. This is a huge advantage if you are in an older home or in the midwest where humidity levels can drastically change from season to season. A solid wood will cup or curl if humidity and moisture levels are not managed. Your installer should do a moisture test before installation to make sure the installation does not fail. All warranties will be voided if this step is not taken. Also, your transitions will need to be considered. Is the new wood floor going to butt up to tile, carpet, or vinyl? The height difference in the two products will need to be taken into consideration. You will have a greater selection of thicknesses in the engineered woods. Engineered wood should be several plys, all wood. If you choose a solid wood, the hand scraped versions are fantastic for a high traffic area with children. Hickory, Red Oak, most Brazilian Species, and even Bamboo are hard enough to take everyday traffic and still look terrific. Good luck!

Who would paint redwood???? That's a total sin against the wood gods. Don't waste money on a premium upgraded wood like that if you want paint. Go with cheap paint grade poplar for half the price. And don't do cream paint to walk on unless you want to repaint every 6 months.

Put in a few French drains where you dig a ditch and fill it with crushed rock to help the water drain. In low spots put in some drains [http://www.homedepot.com/p/Tuf-Tite-16-in-2-Hole-Drain-Sump-with-Grate-and-Seals-2HDS-4/203463511] with pipe running to the French drain. You might also need to bring in 10 yards of top soil along with some sand to raise your yard a bit as you're probably right at the water table level. We've had to do all this as we live in the Pacific Northwest in a reclaimed marsh [a nice word for a swamp] where we hit the water table if we dig down 3". We had to put down about 10 yards of top soil along with some sand to raise our back yard. We also dug a French drain along the back to connect to the associations drainage pipes through the neighborhood. My husband has put in at least 3 of the drains in strategic locations around the yard to help drain off the excess water. Our yard isn't perfect, but it isn't the swamp it was the first couple of years we were here. We have to apply moss killer every spring or it takes over the yard. My husband also puts down lime to soften the soil, and help the water drain easier. He and a friend rent an aerator every summer and do both our yards to help with the drainage as well.

You can leave the handrail the same distance from the wall as it is now. Leave it connected to the newel post at the top; remove the newel post at the bottom, and add what's called a 'return' to anchor the bottom end to the wall. Then add a couple of brackets going up the stairs. The challenge is that the return should match the profile of the handrail, in order to blend, but check at the home center or a lumber yard/mill to see if you can match it (take measurements/drawings/close-up photos, etc.). As for painting the stairs--be careful with "fun" graphics. The treads and risers need to be clearly defined and regular. For example, a plaid or check that doesn't match the tread and riser exactly at each step is a trip hazard and may not meet building codes. People need to be able to see the treads clearly even without paying attention to them. Walking is an unconscious activity and we need to make it as easy as possible. Confusing patterns are a menace. In NYC, they put new edges on treads on one stairway at one train station that were designed to make them less slippery. However, they also made it more difficult to discern the edge of the tread. In 6 weeks, more than 1,400 people fell down those stairs. Then they redid them. Over 90% of injuries on stairs happen during descent. I highly recommend Bill Bryson's great book 'At Home--A Short History of Private Life'. The NYC anecdote above came from Chapter 14--'The Stairs'. Fascinating and amusing book. My house is 100 years old, so I feel your pain dealing with the changes and additions that happened over time.