If you are just starting out in the fishing world, then learning a few knots is critical. I'd say I tie around a dozen knots each time I go fishing (depending on how many bluefish are around.) Often I'm tying these knots at night in a pitching boat. The ability to twist up a good knot in under a minute is very important, especially when there is a big school of striped bass under the boat.
I don't know how to tie a lot of knots because I have no need to learn them. Odds are that you probably do not need to worry about learning a ton of knots either. Having a good grasp on the following 3 knots will easily cover you in almost any fishing situation Cape Cod (and anywhere else for that matter) has to offer.
1) The Trilene Knot
This knot is extremely useful and very simple to tie. I use this knot anytime I am tying a mono-filament or fluorocarbon leader to a hook or lure. The second loop through the eye of the hook or lure is what prevents this knot from slipping.
When the bluefish were in thick a couple weeks back, I had a trip when I tied this knot 20 times in one night!
How to Tie the Trilene Knot
2) The Slim Beauty
I love this knot. The slim beauty has caught tons of big bass and tuna up to 160 pounds without failing even once. That's an impressive knot!
I use this knot for joining braid to a mono-filament or fluorocarbon leader. I also use this knot for joining leadcore to a mono-filament or fluorocarbon leader.
Tying this knot will take some time to get used to. However if you practice, it is possible to tie this knot in under a minute. The slim beauty is a super strong knot for joining two lines together, and I definitely recommend it!
How to Tie the Slim Beauty
3) The Palomar Knot
I use the palomar knot for tying braid to a piece of terminal tackle. This knot is extremely strong and very easy to tie.
A lot of knots that are great for mono are terrible for braid. Braid tends to slip easily, however I have never had braid slip out of a palomar knot.
This knot can also be used with mono-filament or fluorocarbon for tying a leader to a hook, lure or sinker.
How to Tie a Palomar Knot
4) The Spool Cinch Knot
This is a very simple knot that can be used to tie a line to an empty spool prior to loading the spool with line.