For UK freelancers, I've heard nothing but good things about FreeAgent (accounting & invoicing). TopTal (vetted programmer network) seems like a cool source of

For UK freelancers, I've heard nothing but good things about FreeAgent (accounting & invoicing). TopTal (vetted programmer network) seems like a cool source of high-paying clients, though I haven't yet had any jobs out of it (2 weeks in), so I can't say for sure.