Mercury in the Signs and Houses
The short answer
Pick the sign Mercury was in when you were born for every date it was there from 2000 to 2035, or the house it falls in for your rising sign.
Mercury has twelve sign pages and twelve house pages. Never more than one sign from the Sun. It describes how you think, speak and take things in.
Mercury in each sign
Every date Mercury was in the sign from 2000 to 2035, read from the ephemeris, so you can check a birth date against it.
Mercury in each house
Which sign puts Mercury in that house for your rising sign, with whole-sign houses.
Every planet · Cast your free birth chart to see where Mercury sits in yours.