Mario,
Don't worry about soldering, it's actually quite easy (I do it most days in my job at an electronics factory though, so maybe I'm a little blinkered). The trick is not to put too much solder on at once, and not too little... it will depend on your iron and how hot it is.
Make sure you use Flux, you'll be able to get this at an electronics shop. Flux cleans the joint and stops you from getting "dry" solder joints - this is when the solder joint looks "cloudy" and not shiny as it should be. This means the joint isn't right and you'll probably get dodgy sounds from your guitar.
Apply a touch of flux, then apply the iron, and a second later apply solder. All you need is a touch of solder; perhaps another second at the most. Then remove the iron and it's done. Easy!
The best way is to apply the iron to the lug, but not directly on the join. This means that the iron won't get in the way when you apply solder directly to the join, so the lug will heat up and the solder will melt onto the join without the iron getting in the way. I found this out from personal experience! I'd recommend a pair of safety specs too... hot solder does not mix well with eyes!
Hope this helps you my friend. If you have any other questions then just PM me.
Cheers
'87