i didnt use baby oil for dear son. i think is for massaging baby? haha..
Thermometer: get an armpit one and use until baby is 3mth old as below 3mth, their earhole is pretty small, so those ear thermometer might not take accurate reading. after 3-4mth old, baby tend to fidget around, best is to get a ear one, and by then, the ear hole will be bigger for a ear thermometer. For armpit one, any brand will do (we used both watsons hsebrand and Pigeon brand) and ear thermometer, get Braun brand, is more accurate. =)
Nappy cream: dear son has tried pureen brand (given by hospital) and GAIA before we switch to Desitin. So far, we find Desitin the best, not only prevent, and also cure nappy rashes very fast. =)