Put on gloves, knee pads, and protective eye glasses. You'll be working diligently on your hands and knees for hours to complete this project, especially if you're doing a large space. Invest in a good pair of knee pads to protect your knees. Sturdy work gloves will protect your hands from splinters, and goggles will prevent sawdust and other debris from getting into your eyes.
If your floor has noticeable scratches throughout, your best option is to sand down the floor and refinish it. A complete sanding removes scratches, but beware: This only works on real wood floors, not bamboo. If you have an engineered wood floor with a real wood surface, make sure the real wood surface is more than 1mm thick—sanding usually takes at least this much wood off the surface, so a thicker layer is required for a complete sanding.
Oak has always been a popular choice for hardwood flooring. The color is visually appealing, looks inviting, and has many advantages. You’ll find the wood easier to clean, and it easily blends in with furniture and home interior designs you already have. Plus, oak is a good investment if you’re considering selling your house in the future, since the wood can last for many years. Denver Hardwood Floors
Glue down engineered hardwood, alternatively. If you don't want to nail down the boards, you do have the option of using adhesive to put engineered hardwood in place. It's a good choice, but won't last as long or be as sturdy as nailed down hardwood. The procedure is very similar to the nail-down process. Follow the adhesive manufacturer's instructions for installation and drying times. Hardwood Floors