So! You have updated to 0.11.0 of  Minecraft: Pocket Edition and you want to take advantage of the new  skins feature. If you are having trouble getting started, then here is the three ways you can do it.
1. Skin Packs Kind of like the console versions of Minecraft, you can buy packs of skins for 00.99 USD for your Pocket character. So far, there are the City Folk and Townsfolk packs, with the first row of skins free to use. The rest needs money, though.
2. Make Your Own This one is kind of like the phone/tablet version of making a skin on Miners Need Cool Shoes/Novaskin/SkinCraft,etc. You just need to get Minecraft Skin Studio and make your skin with that, or use some other image editing software.
3. Download One From the Internet This is probably the easiest one to do, as it costs no money and gets it done really quick. All you need is to download a skin from the internet (i.e. Here, Planet Minecraft) and boom. You just get the image onto your phone or tablet, and then upload it onto PE by tapping the "browse" box, it will pull up what you would like to use to upload the skin to PE, select your choice of app, and then click your skin file. You can then pick to use the Alex format or Steve format (Surprisingly, it doesn't glitch the textures of Steve arms when in Alex form, so you don't have to worry about that) and then the skin you selected will appear as the character in the Browse box. And all you have to do then is play your game!

If this helped you, please leave a diamond so I know I helped out someone! Hope this helped! If you have any further questions, just leave one in the comments section!