Started my car this morning, took the handbrake off and what sounded like metal banging happened. I drove off, listening for anything else, go over a speed bump on my road, and hear a clunking sound coming from the rear passenger side wheel. My original though is the suspension, as that happened on my previous car, but that was constant banging. I've had a look under the car, and nothing obvious to see. Thinking it might be shock absorber but why would it have made a bang when I took the handbrake off first thing? Handbrake has been fine and no other noise from it since. 

 

Any help is appreciated before I take it to the mechanic. 

I'd guess at rear trailing arms but you need to get the car up in the air and feel around for play on all the suspension.

If you don't have a trolley jack/stands I'd stop here and either buy some or take the car to a mechanic. You're not going to be able to fix much without taking the wheel off lol.

Do you know when the handbrake is on, it holds the car?

It could be that the brake shoe is sticking and might just need a brake service/cleaning

The clanking noise over humps could again be something sticking or suspension bushes on their way