Two very useful items I'd like to draw attention to.
Firstly, the NUJ has revised its Freelance Fees Guide. This extensive list of typical rates for the job is incredibly handy for working out what to charge clients or what rates to expect from the press. I consult this several times a year when something outside my usual range of services drops into my lap and I need a helping hand to price a job.
Secondly, a very handy post from the Freelance Switch blog, which is always packed with good tips and advice. This post on banishing lonely freelance syndrome will strike a chord with many. Working from home can be really isolating so it's important to use all your options to maintain contact with the outside world. You have to create your own water cooler, basically. I use almost all of the 11 tips and techniques - the cat keeps me company (even if he annoys the hell out of me at times by commandeering my desk as his personal bed), I chat on Twitter, Facebook and forums with colleagues and friends, and I aim to get out of the house at least once a day, either just for a walk in the fresh air and to enjoy a change of scenery or to do something - pop to the butcher for my dinner, meet a colleague or client, or drop in on my neighbour (also self-employed) for coffee.
Most of these tips will also refresh your brain, giving you renewed zip as you plough through the editing of that tedious 600-page tome on insurance risk, or helping generate ideas for features if you write. Both of which will, of course, earn you money and send you back to the NUJ fees guide for the right rate...