This is signature guide (Please help me add more to this post):
ALWAYS save in: The .PNG for a file format once you are done.
(It has the best quality and the lowest file size)
Use varied resources in Photoshop, Paint.net, or GIMP: Download brushes,C4Ds and effect stocks or make them. Varied resources makes it easier to make artwork.
(This is how people make good signatures)
NEVER rip a signature: It makes you look like you have no skills if you steal other people's artwork
Best FREE photo/image editing programs: GIMP and Paint.Net
Best PAID photo/image editing programs: Photoshop CS5 Extended
Best OVERALL photo/image editing programs: Photoshop CS5 Extended (Can be disputed)
Add images/renders to signatures: Images are what people like in signatures, so use it.
Use tutorials if you are new to GFX
(Note: this is NOT advertising): If you are new to photo editing and signature making please visit this site to read some tutorials:
[You must be registered and logged in to see this link.] How to add a picture to your signature: Go to an image uploading site like Tinypic or Photobucket and upload your picture,
Copy the URL with the

tags.
Then just paste it into your signature.
Ask for help!: If you don't know how something works just ASK it!
Listen to CC: (Constructive criticism)
This is VERY important! Always listen to the people who are rating your signatures, you can improve your skills ALOT by doing this!
Experiment Don't be afraid to open up Photoshop or GIMP and have a joke around the more you find out the easier it becomes.