Step 1.
Start with the Departing Flights section
The Flexible Date Ribbon at the top of each section shows the lowest available fare on the three days either side of your preferred date. You can click on one of these alternate days if you want to change the departure or return date, and a new search will commence.
For the specific day you have selected, you can see a list of available flights sorted by price, underneath the Flexible Date Ribbon.
You can use the Scroll bar on the right-hand side to see all flights.

Step 2.
For each flight summary line, there are details on airlines, departure and arrival times, flight length and number of stopovers.
Click anywhere on the flight summary line to open for more detail, and to see the baggage and fare type options.
This is where you can add baggage to your preferred flight, or change the fare type.

Step 3.
For most flights you will then be offered to choose the amount of check-in baggage or the product type. Choose the option that suits you buy clicking the yellow "Select" button at the bottom of the fare type panel. This will complete your flight selection process.

Step 4.
If you are booking a one-way flight, you will be transferred to the bottom of the page where you need to click the yellow CONTINUE button. This will take you to the passenger details page to fill out the traveller details.
If you are booking a return flight, you will see the Returning Flights section, where you can follow the same process.
When choosing your Returning Flight you may notice that some flights cannot be selected. This is because some fare are not available as a return flight with your selected departing flight. Only the relevant return fares will be enabled.
When both Departing and Returning Flights are selected, you will be transferred to the bottom of the page where you need to click the yellow CONTINUE button to take you to the passenger details page.