Desoldering is 10x harder than soldering. Just a warning.
Use the Hakko T18-I tip for small stuff. Its what I've been using with the same Iron and I've been able to reasonably do surface mount parts with it. (Admittedly, I have a lot of experience) 350C sounds right for Leaded solder, though 60/40 might be easier to use than 63/37. Smaller diameter solder is also easier to work with.
As for simple instructions on how to solder parts, especially through-hole (Surface Mount are a little more complicated, but the principle is the same):
- Wipe off the tip of your iron on a damp to wet sponge. It should not however be floating. The tip should be shiny
- Place the part held firmly where it needs to go. If its a through hole part, maybe bend a few of the leads over to hold it in place (Don't do this with parts with lots of leads though, they become impossible to desolder). A good mechanical connection is essential to a good solder connection.
- Add a little bit of solder to the tip, so there is a small blob, maybe 1mm in diameter or smaller.
- Place the tip with the blob so it touches both the pad and lead of the part. Slowly add solder to the blob until it wicks out and covers the pad, creates a cone shape around the lead. It should also be a bit concave, unless you've added too much solder. Take the iron and solder away and investigate. Make sure you haven't bridged to another pad and your solder joint should be shiny.
- For parts with a large number of pins, try to tack down corners first, as this will help you hold it to solder the rest of the pins. You can often do Step 4 without adding extra solder afterwards for an intial joint, but once you solder the other pins, make sure go back and redo the initial tacks so they are good joints.