Tips
Good for a beginning comic. And although you draw okay, don't post any more. They don't cut comic standards and are hard to follow.
As for spriting, make the arrows on the speech bubbles a little thinner. It will give you more room and look less chunky.
Um, is Photoshop free? I use Macromedia Fireworks, but that's a very advanced program, so is hard to use if you don't know what you're doing and very expensive. I'm so spoiled ^_^
And I say this with every comic. Instead of trying to think up funny stuff, let it come to you. Look at your day (an interesting day) and comic about ironic, strange and random things that happen. At least for starters. Once you get more experienced, you can try something, but again, let it come to you. Don't try and think it up, the best things always come on their own.
Also a good idea to get a trademark going. SaP has Google and SOAP shoes, I have Cable Ties, so go for something useful and have it appear ever four or so comics when possible.
One more thing. Don't post a comic just for the sake of posting it. Take your time, and if you don't have time, then wait until you can finish it. Don't feel you have an obligation to post comics, you're doing it for yourself. For fun, or something to do. Not because you have to.
Feel free to ask any questions or advice, and I'll be more than happy to assist you in any way possible.