need help replacing rear bike axle and gears

[Danyal]

The axle from the rear wheel broke a few weeks ago. I figured I should maybe replace the gears as well while I was at it. While I was able to find a replacement axle online, I got a little confused with some of guides and info online about whether I have a "freewheel" or "cassette" and the type of tools Im suppose to be using in particular the freewheel/casette remover tool which there are many different variations of. I've put some pictures below of the wheel, so any help identifying the type of gears that I have and the type of tools I should be using would be very helpful.
http://www.tiikoni.com/tis/view/?id=5cfe349
http://www.tiikoni.com/tis/view/?id=3654a74
http://www.tiikoni.com/tis/view/?id=797e363

 

[Smokin Joe]

You have a screw on freewheel and you need one of these -

http://www.ebay.co.uk/itm/Bike-Bicy...sure_Cycling_BikeLocks_SR&hash=item2eca025a62

 

[Danyal]

Hi, the parts i ordered for the bike came yesterday. Had a tough time trying to remove the freewheel. When I went to work my Dad thought he would give it shot and he managed to remove it and put everything that fell out in to a container. Thing is there is a part that came out that I cannot figure out where it goes. In all the videos and diagrams I look at online none of them mention or use this particular part. I put pictures of it below.
http://www.tiikoni.com/tis/view/?id=2300b11

 

[RecordAceFromNew]

They (the 2 ring things) look like dust caps. They go on the hub shell so that there won't be such big gaps between the cones and the hub shell, letting muck and water into the bearings. They are metal and should press-fit in to the hub shell.

Ideally you should replace those ball bearings.

 

[lpretro1]

Just to say the flat side of the dust caps goes inside