Sign up for YNAB - You Need a Budget - and get a month's free subscription (and I confess I get a free month too!). I've just gone back to it after not using it for a while - because I simply can't manage my finances without it. It works on basic principles - every pound or dollar has a job to do - and you can't allocate it until you actually have it. If like me you know its coming so you spend in anticipation on something you really want - but then you forget that big bill that's heading your way - then you could really use this budgetting software. Give it a try and get yourself a free month....
On Ziffit - or in UK World of Books - can use link to get ยฃ5 extra on your first trade over ยฃ10. I'll also get ยฃ5
Sell your 2nd hand books and make some cash - and buy more books!