Hi,
You have actually named a few of the best things to beginning bottling foods. For apples, plums and peaches you do not need to worry about pressure canning, they have enough natural acid. As I am in the US I do not know the name Kilner, but from your description it sounds like the right style jar. It has a two piece metal lid, a flat lid and a screw on ring, right?
If you have the right jars, it really isn't daunting at all, especially if you begin with fruits or something pickled. All you would need to do is prepare your fruit as you normally would do, wash and then heat the jars in boiling water, scoop the fruit into the jars, leaving 1/4 inch head room, clean off the edge of the jar and put on the lids. Then just submerge the jars in a pot of boiling water, making sure the water is at least 1/2 inch above the top of the jars. Bring the water back up to the boil and leave them in for 20 minutes. Lift them out and let them cool. As the jars are cooling you will hear the lids "plink" as they seal. Then your fruit will be safe to store on the shelf for two years. I think that the only difficult thing is dealling with boiling water, you want to be careful to not get burned. You can get a Jar lifter tool that helps you do this without burning yourself (you can just type "jar lifter" into your search engine to find one).
In an earlier post in this "Food Processing" forum I posted a couple internet links to sites that give very detailed instructions. If you can not find that post, I would be happy to resend them.
Please feel free to ask any questions you would like, I would be thrilled to be of help.
Ruth in New Hampshire