We teach bar chord shapes after open chords in our guitar lessons at Do Re Mi Studios. You play bar chords by pressing the first finger against five or six strings. It is essential that you master bar chords. You will definitely find them in songs as you progress. To find out how to create the sound of a bar chord check out https://www.youtube.com/watch?v=rIooJjKst_4
I have divided the chord shapes in this article into three types: major, minor, and 7th. Each of these has its root either on the 5th or 6th string. The root is the foundation note from which the chord derives its name. The bar chords in this article are on the first 3 frets of the guitar. However, you can play them on any fret.
Major Bar Chord Shapes
Root on 6th String
The chord shape below (as played with the bar on fret 1) is F. It is chord F because the note pressed on the 6th string 1st fret is F. For this chord, place your first finger over all the strings. Then, place your 2nd finger on 3rd string 2nd fret and your 3rd finger on the 5th string 3rd fret. Finally, place your 4th finger on the 4th string 3rd fret.
Keep your thumb behind the 2nd fret to help you bar the 1st finger down.

Root on 5th String
The bar chord shape below (as played with the bar on fret 1) is Bb. It is chord Bb because the note pressed on the 5th string 1st fret is Bb. For this bar chord shape, place your first finger over strings 1 to 5. Then place your 3rd finger over strings 2 to 4. Mute the 1st string with the third finger. Out of all the chords discussed here, we teach this bar chord in our Sutherland Shire private guitar lessons last. This is because it is the hardest to play. It will require a little practice to get a good sound. Make sure your thumb is behind the fretboard for support.

Minor Bar Chord Shapes
Root on 6th String
The bar chord shape below (as played with the bar on fret 1) is F minor. For this bar chord shape, place your first finger over all the strings. Then add your 3rd finger on the 5th string 3rd fret and 4th finger on the 4th string, 3rd fret.

Root on 5th String
The bar chord shape below (as played with the bar on fret 1) is Bb minor. For this chord shape, place your first finger over strings 1 to 5. Then place your 2nd finger on 2nd string 2nd fret and your 3rd finger on the 4th string 3rd fret. Finally, place your 4th finger on the 3rd string, 3rd fret.

7th Bar Chord Shapes
Root on 6th String
The bar chord shape below (as played with the bar on fret 1) is F7. To play this chord, place your first finger over all the strings. Then, place your 2nd finger on 3rd string 2nd fret, and your 3rd finger on the 5th string 3rd fret.

Root on 5th String
Below (as played with the bar on fret 1) is Bb7. For this chord, place your first finger over strings 1 to 5. Then place your 3rd finger on the 4th string 3rd fret and 4th finger on the 3rd string, 3rd fret.

For a more complete chords chart, check out http://www.vexflow.com/vexchords/