#1 - Go to any book on site and click on it. The Book Profile Page will open. Underneath the title and author name you will see four grey icons, along with the star rating field. The second icon is an open book symbol. Click on this to indicate that you are 'Currently Reading' this book. The symbol will turn red and the book will be automatically added to your 'Currently Reading' list.
#2 - From your Profile: There is a small plus '+' sign under the left hand corner of the book image in the currently reading section. Click on this '+' and a pop up search box will appear. Type in the name of the book you are currently reading. Select the book from the list that appears. Refresh the page to see that the new book has been added to your 'Currently Reading' List. To see the book, click the right/left arrows in the lower right corner. You will also notice that if you had '1 current' book, the words under the book will now say '2 current'.