If your floor is real linoleum, it has a finish of hardened linseed oil with characteristics similar to those of traditional oil-based varnish. If you spill glue on it, the difficulty you'll have removing it is commensurate with the type of glue it is. You may be able to soften it with heat or a solvent or harden it with ice to make it easier to chip; in the end, some scraping will be involved.
Dissolve Glue With Solvents
Some adhesives, such as tile mastic and wood glue, are water-soluble and will soften if you can keep them wet long enough. An easy way to do this is to soak a towel, lay it on the damaged area and keep it wet by spraying it with water periodically. Eventually, the glue may become soft enough to scrape away, using a plastic paint scraper that won't scratch the linoleum. If water doesn't work, try mineral spirits or paint thinner; neither will damage linoleum. You may have to resort to acetone or lacquer thinner for some types of glue, and these require more respect. Dab the solvent on the glue -- not on the surrounding flooring -- using a cotton swab.
Melt Glue With Heat
Some adhesives, notably contact cement, are heat-sensitive, and you can soften them with a hair dryer on medium to high heat. It's important to avoid overheating; that will also soften the linoleum, which can cause the adhesive to amalgamate with the hardened linseed oil. Monitor the consistency of the glue while you're heating it, and remove the heat and scrape as soon as it softens. It's safer to scrape with a plastic scraper, but you can use a metal scraper if you keep the angle of the handle low with respect to the floor and avoid downward pressure on the blade.
Harden Glue With Ice
Some types of glue, such as construction adhesive and polyurethane glue, don't respond well to heat or solvents but become brittle when exposed to ice or dry ice. Keep the ice in a plastic bag; place the bag on top of the glue and leave it there for 5 to 10 minutes. When you remove the bag, chip the glue off the floor using a plastic putty knife and a hammer; work the knife blade under the glue and give it a sharp tap. You may prefer a metal blade, but it can potentially damage the floor, so use it with caution.
Glue on Vinyl Floors
Not all floors that look like linoleum are actually linoleum; many are vinyl, and if that's the case, you should be more careful about using solvents. Avoid lacquer thinner or acetone, which both melt vinyl. It's safe to use ice and heat, but avoid scraping or tapping with a metal blade; it may crack the surface or remove part of the pattern, which is imprinted on the surface. If the glue has hardened, you may have some success scraping it off with a pull scraper; use light pressure on the tool and don't allow the blade to come in contact with the flooring.