In Latin, the word for pray, orare, simply means to ask, and yes, we ask those in Heaven for their intercession for our needs, just as we ask those on Earth for their intercession for our needs as well. Certainly Christ, being God, is the highest authority, but asking others for their intercession does not contradict this because they are interceding with Christ for us. In other words, they are not competing with Christ for mediatorship with the Father; rather, they intercede with Christ, and Christ intercedes with the Father.
It is certainly true that we should go directly to Christ for our needs, but just as we ask (or should ask) our friends and relatives to pray for us, we ask our Heavenly friends and relatives to do so as well. In Revelation 5:8 we see the elders in Heaven carrying to God as bowls of incense the prayers of the saints (holy ones, which includes those on Earth). In Jeremiah 15:1, we see that Moses and Samuel — who lived in different time periods, it will be noted — stood before God to intercede for Israel.
This is a topic we've covered before. For example, see:
Also see this Catholic Answers tract on the topic: