If you have wood floor underneath your carpets there is a couple things that you should look for.
1. Stains: Such as pet urine or spilled drinks, etc. stuff that has seeped into the wood discoloring it. If the wood floor is not already finished you will likely not be able to get these stains out. If it is already finished, the stain may have not seeped down into the pores of the wood, and you may be able to get it off.
2. Deep dents and or scratches: If you have any large dents or scratches sanding the floor will not eliminate them. Small scratches and dents can be sanded out of the floor.
If you do not plan on using the hardwood under your carpet or you don’t have any under the carpet you have lots of options.
1. Bamboo: I’ve never installed bamboo flooring but I hear it is pretty good and more durable and resistant to spilled drinks, etc than standard hardwood. You still need to take of the floor though as you would with a regular hardwood floor.
2. Salvaged Wood: Unfortunately I don’t know a whole lot about this but is likely a cost effective solution.
3. Composite/Laminate flooring: This is cost effective and nearly maintenance free but is not as nice looking as real wood. Although if you have pets with nails will not scratch as hardwood would.
4. Oak flooring: Hard wood and is fairly resistant to dents and scratches and lots of different color variations.
5. Pine flooring: Is a soft wood but looks nice in older homes because it generates lots of character.
6. Maple flooring: Its also a hardwood and has a closed grain which means its less likely to wear overtime.
7. Many others…......
If you are going to refurbish the wood floor under your carpet it is something you could absolutely do yourself. You will first need to rent a drum sander. Sand the whole floor eliminating any stain and top coat that already exists and any small dents or scratches. This is probably the most important part if you want to be sure your final stain is consistent. Make sure when you sand you don’t have any color variations in your wood floor other than the wood grain of course or it will show up when you put your stain down. Once you sand everything you need to get rid of all the dust and debris you generated. I usually do this by mopping the floor several times. You are then ready to stain and put on your clear coat as you would with any wood you stain. If you want to hire a professional Lowe’s or Home Depot generally contract out to professionals but I would require all of them to provide and/or show you some of the work that they have already done.
Good luck!!!!