Tutorial for a simple animated slideshow?

If you have the Creative Suite Lightroom has a very good slide show engine and it's very fast. If you just want to slide images in and out or wipe between them Premiere Pro is by far the fastest way to do that. If you want a different move on every image and all kinds of fancy transitions between images, which in my opinion very quickly turns the transitions into the story instead of the images, then you can customize every move and every layer in After Effects. Make a move you like and save it as an Animation preset. Invest in a set of animation presets or scripts, or buy a template if you want to save time. Otherwise, get familiar with AE's UI, 3D space, animating the camera, and transition effects. If you are really new start with the User Guide.

There are transitions in AE but for what I saw those transitions can be very easily done in Premiere.

You may want to consider using Premiere transitions to bring the slides in and then After Effects for the text.