the best advice I wish I had had from the start is to go slow. Your style will change, and you'll look at the stuff you bought a year from now and wish you hadn't bought it. Also, I believe in buying the best quality. Many of us have bought cheaper stuff and then just replaced it with better quality, wasting money. Here's my thoughts. Keep in mind that I'm a SU demo, so I'm biased!
1. try and get to some workshops/classes before you spend much. You'll get a feel for what you like.
2. Get a good quality black waterproof ink pad and a reinker. SU's is not waterproof even though they claim it is. (sorry, but that is why they recommend Staz on for watercoloring). Get Staz On or Memories.
3. Versamark pad. You'll reach for this a lot. It will make a watermark on the page and will also be your go to pad for embossing.
4. Invest in a good paper cutter. Do some research. pm me for advice. I've done a LOT of research on this issue.
5. If you are going to buy SU or any stamps that need cutting, buy the SU scissors (or KAI) same thing.
6. Invest in good quality paper. SU's is the best. And, buy their coordinating inks. It will save you a lot over time. Just get Whisper White to start with and one color family at a time. Try out the stampin spots to get a feel for the colors.
7. If you are going to get a heat gun, get the Heat IT by Ranger or check into the cordless one at Bonnie's Best Art Tools (on line). The Heat It is so quiet and doesn't blow a lot of air around. I haven't tried the cordless, but am very intrigued.
8. There are a TON of stamp companies. I stick to SU because I'm creative impaired and there are literally thousands of examples of how to use their sets on the internet. However, you will find lots of stamps -- some even nicer (!!) elsewhere. Check out
www.addictedtorubberstamps.com and drool for a while. Remember, though, a great stamp is useless, if you don't know what to do with it. That's why I've learned to stick with SU.
9. This is an addiction and I'm not kidding. Once you get started, you will need SPACE, TIME, and CASH!! Figure out now where you are going to put the stuff. It's like a bacteria -- it grows!!
10. Buy used if you can. Used stamps work great and there are tons for sale here and elsewhere.
11. Enjoy -- it is a wonderful hobby.