I purchased this soldering iron yesterday and after doing some research I'm not convinced it is safe to use on electronics. It doesn't state the wattage anywhere and I can't find it online. It only says that it heats to 950°F, which I'm pretty sure would destroy a PCB. Should I return this and buy a 25 watt soldering iron?
It's inappropriate for electronics.
That said, if you have a deft touch it's possible to use such an iron without destroying the copper-laminate adhesive, but I would not recommend it. For example if you tried to desolder something the board would quickly be ruined- pads lifted.
You could reduce the power to half by wiring a 1N4007 in series with the mains, but a better choice would be to buy a soldering iron or solder station that has closed-loop control of the tip temperature, preferably adjustable. The 25W iron you mention would not have this feature. Try to pick something with replacement tips you can get locally (or at least readily) in various sizes and types.
As stated previously, I would really avoid using that iron. I've had many experiences using poorly maintained or cheap irons, and it can be incredibly frustrating. This is especially true when it destroys something you poured time and money into. I would consider investing a little bit more money in an iron with variable output. They are typically characterized by a device with a base (not those ones that plug directly into the wall). They can cost 2-3 times what you paid, but I think that it is definitely worth it in the long run. I used a Weller Iron when I was starting out, and it worked quite well.
Currently I am using a Hakko FX-888D Iron which was a great investment, reducing time spent fixing mistakes. For the price, it's a great tool. That said, it is not necessary for beginners and the price reflects this.
To recap, it is not necessary to spend a ton of money on a soldering iron when starting out. Instead, look for an iron that has had positive customer reviews and performs well for the cost. Look for guides and tutorials online when you begin soldering, and use good technique. I also recommend finding a tool with variable temperature control. This combined will give you satisfying results, and make the learning process much more enjoyable all around.
It depends on what your soldering, if its wires and components with long leads then go ahead, but don't "dwell" on any one spot for too long. Don't think about soldering any IC's you'll destroy them. Another problem that you might run into is lead vaporization. Lead melts at about 621 F (327C) and begins to vaporize above 1100F (593C) so get an expensive air filtration system. Or just get a new iron, they have cheap semi-decent Chinese ones available from several places.