Judith..I too love Philos/Monsteras..If you received a piece w/stem, then you can just set in water..keep in bright but out of direct sun area..You should see roots in 10 days or so..
Some ppl use soil, but I prefer water..After roots are about 3", then it's safe to pot in a well-draining soil, and not too large a pot. Give a very mild solution fertilizer, then place in bright light..Toni