You can have a flooring company come in and do a screening, which is a light surface sanding and put on just a new topcoat.

Brand of hardwood? What type of hardwood (engineered or solid)? How old is the floor? Can you send photos? Cleaning hardwood is the easy part: pH neutral hardwood floor cleaner .... like the stuff you can purchase from any hardwood flooring manufacturer.

In theory a site finished (or factory finished with urethane/polyurethane/oil treatment) floor can have a treatment like Deborah suggests. If it is finished with Aluminum Oxide, there are fewer choices.

Here are a few things you should NOT DO:
Do NOT use steam cleaners
Do NOT use "magic erasers"
Do NOT use Murphy's Oil soap
Do NOT use "all purpose"/"general cleaning products"
Do NOT use "soap and water"

Send photos and some info on the brand/make/name of the floor in question and we will help a bit more.

We just bought the house, so I have no idea what kind of floor it is. in my old home we had a floor installed and the installer said steam was fine and what he used on his floors. it is in the kitchen so gets lots of use. thanks.

Steam cooks a hardwood finish. It causes it to age faster and can often times cause hazing and cracking. A finish that should last 25 years can be reduced to 15 years or less with steam. Even on steam cleaners they state they should not be used on wood (but you have to find the small print on the website to view this information).

Photos would be very helpful. If you are seeing wear, then the finish is probably a urethane/polyurethane of some sort. A quick fix (should last for 7-12 years....long enough to get you to the next sand/refinish) is a buff and coat. It is half the price, half the time and half the materials needed for a full sand/refinish.

A professional comes in and does a light sanding (buffs up the old finish...does not remove it) and then applies a single coat of polyurethane/urethane (what ever is compatible with your finish). You allow it to cure (several days to several weeks...depending on the finish type) and then move back onto the floor.

If you like the colour and wish to keep it...then go with a buff and coat. If you are planning on changing the colour soon (inside of 5 years) then skip the buff and coat, and wait for the budget to come in to do a full sand/refinish with the colour you want.

Without seeing the marks on the floor (and the wear) it is very hard to give more information than this.

People see the Swiffer steam cleaner ads where people are cleaning wood floors, and assume it's safe because they saw it in an ad. I bet there are thousands of floors that will be significantly aged due to Swiffers in the coming years.