How do I upload .png files/images to my site?

Hello: I am having the most difficult time. I have looked every where for an answer. So, I am hoping someone will be able to help me here.

I have made some text images in Gimp for use in my theme as tag lines. I found out that .gif won’t work because that format leaves the edges of images looking rough and lack overall quality.

After a nightmare of a time I finally was able to upload my text images to Photobucket without that annoying white background present… ahhh at last the transparency was working.

However, once I move the image from Photobucket to my site the image becomes Very Blurry.

My image size as made in Gimp is say 338×45 but when I open it in Photobucket it says that the image is actually 338×42. So, I thought maybe that was causing the blur issue so, I resized the image within Photobucket but again, once loaded to my site not only was it blurry but it’s not nearly the right size.

Also, when I load the image in the back office if it’s not going to work that thing which says something to the affect of: “image20%somethingimage20% shows up. ?? What is that about?

I am pretty sure the issue may be in the HTML but I have no idea how to fix it or anything near to that affect.

If someone could please share the “secret handshake” with me with regard to how to simply, quickly, easily and within a timely manner upload High Quality, Clear and Crisp images to my site I will build you a monument in Times Square and go there every day to worship at your feet!!

Thank you so much for your time which I truly value. I think people that take time to share knowledge with others really rock!!