This is going to be a SIMPLE "how to picmonkey" guide. It's not an in depth but it will have enough to get you started!
Step 1) Create your image. This step is pretty simple but I'll provide some guidelines. **Disclaimer all of this depends on your individual blog and width of your section these are just general sizes!!
Header size = 1100px by 300px (but it depends on YOUR individual blog layout)
Button size= 300px by 300px
Signature= 150px by 75 (sometimes bigger or smaller depending on font but signatures usually only include words)
Gadget icons = 295px by 100px (These are your sidebar widgets)
Step 2) Once you have decided on the size, save the file as either a jpeg or png. I'll explain the difference in simple terms: JPGs tend to be smaller file sizes (which can be important) but not as good quality, but not so bad quality you'll notice a huge difference. PNGs blend the pixels better then jpgs therefore they're a higher file size but also a higher quality. So decide what your file needs to be. If it's a small image to begin with it's not a big deal. If you don't have a quota to meet of storage space why not make them all pngs?
Step 3) open picmonkey and select Edit a Photo. The great thing about picmonkey is that it's FREE to use, some of the features (for more fonts, overlays, and editing software, you have to purchase "the Royale") but for general use it's free. Trust me I used it for a long time and didn't pay for it, I only recently paid for it. So click Edit a Photo and it will bring you to the next page:
Step 4) Start adding things to your image. As you can see I've shown you one image that I had already created (my button for when I start my link parties THIS SUNDAY) Change the colors, the fonts, use overlays and textures. You'll be amazed at what is there for you!
Play around on picmonkey and learn to do things!!
Step 5) Once you're done and you've finished it and like it, go ahead and SAVE. So you'll click the save or save as on the previous screen and it will bring you to the current image. You'll name your file and again make a decision on JPG or PNG!
I hope you enjoyed my very SIMPLE instruction on how to use picmonkey. If there are some how to's that I have on my blog that you want me to walk you through, let me know and I'll see about writing it in.