If you do music already, you will understand that chords often come in groups. Most songs on the radio will often use the same 4 chords , and just repeat the loop. In fact, a lot of songs even use the same groups of songs which makes life very easy.
Some music has pictures of the chords which is handy, others just have the letter of the chords. First of all, lets work out how to turn the pictures into a chord.
Here are 2 chords. If you hold your ukulele up by its neck facing you, then these images are literally an image of your ukulele. The top darker line is the 'nut', the line on the far right is the 1st string (or bottom one) etc. Each horizontal line is a fret.
So now from those images, you can see the chord C is played by just putting your 3rd finger on the bottom string on the 3rd fret. Very easy! We use the 3rd finger because it's easy chord, it keeps the first two fingers available ready to move to the next chord.
F chord requires 2 fingers, the first finger goes on the 2nd to bottom string (2nd string) on the 1st fret, and the 2nd finger to go on the top string on the 2nd fret.
Here is what they both look like (click to enlarge)
Wow, now you can strum 2 chords already! You are really doing well!
Sometimes the chord charts do not show you which finger to put where, you just need to work it out yourself or google and see how others do it.
I found the best method for changing between chords is look for the common finger between the 2 chords. If you can keep a finger on a string at all times then you are less likely to loose your place.
eg going from Am to F, leave the top finger on, and just move the bottom one. Going from F to C, keep the top 2 fingers on the F chord, put the C down (this is why we used 3rd finger) and then lift the others up.
Best thing you can do now, is practice practice practice. It may help to put sticky tape over fingers if they get sore.
Next -> Step 5 - Adding Chords to the Collection