In this video, plant specialist Gretchen Mason reviews the basics for watering philodendron. Many plant owners accidentally harm their plants by watering too much. This concept can be applied to multiple houseplants.
1) Check the top of the soil to ensure it is dry, then use your finger to make sure that the soil is cool and dry, it should not still be damp.
2) Carry your pot to the sink, and water the plant until water pours from the drainage hole.
3) if you are placing it back in a decorative pot, leave it in the sink for a while until the extra water drains out.
Repeat this process, checking the soil every few days to a week at a time until you have a feel for how often your plants need water.