When to use which lens, guidance, please.

Pentax K-r dslr. Lenses are 18-55mm and 50-200mm. Having used only a fixed lense previously, I am now wondering whether there is a general rule of thumb for the use of the two lenses. When is it best to use the 18-55mm and when to use the 50-200mm lense? Kind regards.

The 18-55 is obviously the one for wide angle shots and the 50-200 for when you want to zoom in a long way. Just try the lenses and you'll soon see for yourself

I have read that around 50mm the tele-zoom is not at its best, so probably best use the 18-55 for "standard" shots. But others may feel differently...

Rule of thumb: whichever lens is currently fixed to the body is not the one you need to frame the shot how you want to.

The 50-200 zoom is likely to be more useful in taking close-up portrait shots, wildlife and things far away from you.

The 18-55 is most likely to be used in taking shots of landscapes, outsides of buildings, inside rooms and 'groups of people' shots.

Either lens can be used for anything... try the 18mm setting to take a close-up of someone's face (it's unlikely to be a flattering photo, but do try it!).

thanks for all your advice guys, it is much appreciated. As you will come to see, I am a complete novice at this game and have lots of intelligent [that's doubtful] questions to ask. Kind regards.