Hi Cathy,
"soi-même" is "oneself" or "yourself" in English. For example:
"Pour l’apprendre aux autres il faut le savoir soi-même." -- To teach it to others one must knkow it oneself (or: you must know it yourself).
Or, in another example:
Il vaut mieux le faire soi-même. --It’s better to do it yourself.Does that help? -- Chris (not a native speaker).