For single-sided flyers and ads, I simply layout using Photoshop since it has great typesetting features such as optical spacing, kerning, leading, etc. that MS Word and similar word-processing apps lack. Yes, MS Word can be used to create nice layouts, but it's clunky, IMO, especially anyone who wants/needs to typeset well-crafted heads and type that won't resemble something done with a typewriter. Best of all, you have more control over your images, color space, etc. InDesign and Illustrator are also great tools for design but both come with fairly steep learning curves if you are not versed with the jargon or basic graphic design concepts.
In Photoshop, you can output your file directly as both PDF and jpg files quite easily.
For good tips on layout & design, take a look at
https://www.bamagazine.com for great info on basic design. John McWade transitioned from the stoneages of design (cold type) into the world of digital starting with PageMaker 1.0, Serial number 2 or 3. He's a wiz and continues to share his wealth of knowledge!
