... Wellers ain't bad but I like the auto temp controlled adjustable irons from "GC Electronics" best of all.
As our mod points out, you NEED either adjustable temp (best) or an assortment of tips (at least).
There are several things to consider when approaching the fine art of soldering, such as:
A larger tip will lose less heat during the transfer to the solder point.
But a finer tip (at a higher temp) is needed for working on tight groups such as pins.
(And don't even think about soldering chips onto PCBs until you're good)
A finer point at a higher temp will do (roughly) the same heat transfer as a larger tip at a lower temp.
All my soldering is done with 80 watts at temps between 500-850 degrees Fahrenheit depending upon the application.
Lower temps heat up surrounding elements more (before solder melting point is reached) than a higher temp will.
(You want to "touch and go" NOT sit there heating up everything in the surrounding area) ....
Soldering Flux is your friend !!!!!
Always heat the wires and pads (simultaneously) and do NOT ever heat the solder directly with the iron when making connections.
Solder is melted when touching the heated elements (wire/pad or wire/wire) never by the iron.
Always clean your hot iron (on a wet sponge) and apply fresh solder to it before each and every solder joint is made !!!!!!
Always apply fresh solder directly to the iron's tip before shutting it off
Practice practice practice first before working on circuit boards. Too much heat for too long will make the traces raise up off the circuit boards, ruining them.
Trust me on these tips, I've been soldering for over 45 years and I'm also certified in soldering by NASA