There's no need for this subject to be either complicated or intimidating. You can complete the rigging of virtually any ship model with two knots: the reef knot (otherwise known as the square knot) and the clove hitch. Both of them are extremely simple - just about the simplest knots there are. Describing knots in words is notoriously difficult, but any book or website (I'm sure there are some that cover knots) should make both of them clear in a matter of seconds.
The clove hitch is used to secure a piece of rope to some object in such a way that both ends of the rope remain free. It relies on tension on both ends of the rope to keep it tight. Its principal use in a ship model is in tying ratlines to shrouds. If you're using the pre-formed "shrouds and ratlines" that came with the kit, you can forget about it.
The reef knot is used for tying two pieces of rope together, tying both ends of a single line together, or tying the end of a line to an eye, spar, block, or other fitting. In modeling terms, the reef knot is for everything for which the clove hitch isn't appropriate. If you aren't rigging your own ratlines, the reef knot probably is the only one you'll need.
In a real ship, of course, dozens of different knots were used for different purposes. But in a model those two probably will do everything you want. Oh - occasionally you may need to tie a knot in the end of a line to keep the line from passing through a hole. (E.g. - when rigging a lanyard for a pair of deadeyes.) Knots like the stopper knot or the Matthew Walker knot are used for that purpose in real life, but in a model you can get by perfectly well by simply tying a reef knot with a couple of extra turns in it.
I've seen quite a few gadgets designed for rigging ship models, but I've never found anything to take the place of a good, fine-pointed pair of tweezers. Until you get some practice, two pairs of tweezers - one bigger than the other, perhaps - will come in handy.
Seizing lines isn't really difficult once you get the hang of it - and, especially in the standing rigging, it makes quite a difference in the finished model's appearance. The trick is to work out some means of hanging on to the line (or lines) being seized, so you can use both hands for the seizing itself. Modelers use alligator clips, hand vises, and even clothespins for that purpose. The other trick in doing a seizing (be warned: this is ten times as easy to do as it is to describe in words) is to make the first full turn lock the end of the seizing line in place. Pass the fine seizing line between the two parts of the heavy line that's being seized. Hold the bitter end of the fine line alongside one part of the heavy line. Take the fine line all the way around both parts of the heavy line, and around itself. That should hold one end of the seizing line tight. When the seizing is done, tuck the end of the seizing line through the loop made by its last pass around the heavy line and pull taut. Now both ends are stuck. But just to be safe, I recommend putting a tiny bit of Elmer's glue on each end and letting it dry before cutting off the excess thread.
Another adhesive that comes in handy is superglue (CA). I recommend using it sparingly for actually securing lines, but it's extremely useful in getting lines ready to rig. If a line has to go through one or more blocks, deadeyes, eyebolts, etc., put a drop of superglue on the end of it and wipe most of the glue off quickly. The superglue eliminates any fraying, and makes the last half inch or so of the line stiff. That's like having a built-in needle.
Consider replacing some of the rigging fittings that come with the model. Lots of experienced modelers get rid of the molded deadeyes and lanyards, along with the plastic-coated-thread "shrouds and ratlines." If this is your first sailing ship, you may not want to do that. But your life will be easier if you replace the plastic belaying pins with brass ones. The plastic ones - even if half of them weren't busted before you opened the box - are likely to snap when you try to tighten the lines that are secured to them. Various companies offer aftermarket belaying pins; my favorite is Bluejacket ( www.bluejacketinc.com ). Unfortunately brass belaying pins aren't cheap, but they vastly improve the quality of the modeler's life. Plastic eyebolts also tend to snap. It's easy to make replacements from brass wire. Hold a piece of wire over a candle flame for a minute, to soften it. Then bend it around some sort of mandrel (a set of drill bits, #60 through #80, works well for the purpose) and twist the ends into a short "pigtail." Superglue the eyebolt into the deck (or hull, or whatever), and it will resist any yank you give it.
Ship model rigging is full of steep but short learning curves. If you give them a chance, you'll find that your eyes, brain, and fingers actually learn pretty quickly. It may take your fifteen minutes to seize a big eye in a piece of heavy thread the first time you try it, but I'll bet the second one takes no more than ten minutes - and shortly you'll be doing the trick in less than a minute.
Hope that helps a little. Good luck. It's a great hobby.