Cleaning- Always clean your new album as soon as you open the package. New albums are full of contaminants such as dust, pieces of vinyl, paper, etc. These items need to be removed so as not to damage the album. Always clean your album in a circular motion following the grooves. Never clean an album from the center out as you would a CD. Always use a mild detergent designed specifically for your albums. Likewise, always use a soft cleaning pad that is designed for albums.
Storage- Always store your albums vertically. Never lay them flat (the forces of time and gravity will warp an album laying this way). Always store your album inside its' protective sleeve (preferably an anti-static sleeve), and always store this sleeve inside of the cardboard jacket. Purchase a plastic outer sleeves to store the jacket in. This offers the best all around protection for your album and cover. If you have many albums, purchase crates that are designed solely for the purpose of containing them.
Shrink wrap- When opening a new album, be sure to entirely remove the shrink wrap. Many people leave this on thinking that they are further protecting the cover. That is what the separately purchased plastic sleeves are for. By leaving the shrink wrap intact, it can slowly tighten over time, and can even put enough pressure on the vinyl to warp it.
Handling- Always handle vinyl as you would a CD. Hold it between two hands on the edges. Never pick up a vinyl LP with one hand. Never touch the playing surface. The best way to remove an LP from its' protective sleeve is to let it slide out to where the spindle hole is revealed (place your palm or torso in front of the opening to keep the disc from accidentally sliding too far and falling). Place the middle finger under the spindle hole, and allow the other fingers to contact the paper label for balance. Allow the thumb to contact the outer edge of the LP. The LP can be safely handled with one hand in this manner. If the LP will not slide from its' protective holder, use the less desirable method of pinching the outermost edge of the vinyl between the thumb and forefinger (Do not allow fingernails to contact surface). Once removed, used the above methods of handling. If you have an automatic turntable capable of playing multiple LPs ... never, ever use that function! Never stack vinyl on top of vinyl! This is an outdated convenience that was used in an era when vinyl was played 'til it wore out, and then thrown away (or traded in) for a new copy.
Defacing- Any type of defacing will detract from the value of your album. Never write on or place stickers on any part of the album cover or label. The two most common forms of defacing are dogged corners of the album cover caused by rough handling; and spindle marks caused by laying an album on the spindle and sliding it around until you find the center hole. To avoid this, place the album's center hole near the spindle. Look through the center hole until you see the spindle. Slowly put the album down over the spindle while keeping your eye on it through the center album hole for guidance.
General- Always use your turntable arm lifter when setting the tone arm onto the album or lifting it up. Never carry your albums in an automobile over extended periods. Never store albums close to any type of heat source ... such as a radiator, heating vents, sunlight through a window, etc. Never store vinyl without outer protection. Never allow direct or indirect sunlight to strike your vinyl or cover for extended periods; or allow either to be exposed to the elements (This rule makes buying an LP from an outdoor flea market vendor a dubious prospect).
Warp- The big enemy of vinyl. Always handle your vinyl and store it in such a manner to avoid warp. Should a small warp appear, and it doesn't noticeably alter the sound ... it's just something that you'll have to live with. When vinyl was king, even many new LPs had a slight warp. This won't affect the sound on any but the super high end turntables. For vinyl that is warped beyond playing; here is a trick. Acquire two heavy pieces of glass (such as those used in glass shelving 1/8 inch thick or so) each larger than the LP. Take the pieces of glass outside on a good sunny day and make sure that they are totally free of dust, paper lint, etc.. Lay the glass down somewhere where the sun will hit it (and it will be out of the path of marauding bands of children or animals) Place your good for nothing else vinyl problem on top of the glass. Lay the second piece of glass on top of the vinyl creating a sandwich. Now wait. And wait..... and wait some more. Eventually the sun will cause the vinyl to soften, and the weight of the glass will cause the warp to lessen (and in some cases, completely be removed). Bring this sandwich inside and set it in an out of the way place to cool. In any case, a worthless piece of vinyl will at least now be playable. Words of caution: although this method will work, it is never recommended for an LP with only a slight warp that does not affect the sound. And finally, it must be done in sunlight. Never try to use artificial heat, as this will damage the vinyl. Set it outside, and be patient!