There are a slew of knots out there but knowing a few good ones is enough. The Little Red Book of Fishing Knots is good and can be had from Amazon for $4.96: http://www.amazon.com/The-Little-Fishing-Knot-Book/dp/0969873409. Alternatively, Google: fishing knots in diagrams, or, fishing knot pdf, and you will be shown. Alternatively, look at page 76 in my Maximum Salmon, also at Amazon: https://www.amazon.ca/Maximum-Salmon-Fishing-Alaska-California/dp/1550174037.
Reel knot – tie a simple overhand knot in the tag end of the line, backing or other line that will be laid down on the reel first. Thread the line around the reel drum and tie another overhand knot, this time around the line itself. Pull and, voila, a sound simple knot that will not come apart. And should a big chinook spool you, wind the ball-bearing snap from another rod around the reel seat a couple of times above the reel and clip the clip and assign the first rod to the sea and continue playing the fish from the second rod, as once happened to me.
Palomar – this simple strong knot is best used for lures tied directly to the mainline for use in either salt- or fresh-water or for end snaps on the mainline. Form a loop in the mainline and push it through the metal loop or swivel on the item. Form a loop from the line through the swivel and tie an overhand knot, then slip the loop around the item being tied to, and tighten. A good strong knot with great breaking strength because the knot itself does not become a breaking point.
Figure eight knot – perhaps the most useful knot in all of fishing. I stopped using surgeon’s knots one day when, on five successive casts, I landed the fly in the bush on the other side of the river, on the first cast, and yanking simply broke the knot at the flyline, this on a stepped down and thus three different test mono leader constructed on the spot with surgeon’s knots. After half an hour and lots of expletives, I decided never to use a surgeon knot again. I had done the same earlier in my fishing with Blood Knots.
As a figure eight knot results in a loop, you can use it anytime you need one – stepping down leader; martingale; alternative to a Palomar. Make a loop in the tag end line, wrap it around your first two fingers, hold the line with your thumb of the same hand, take the line off your two fingers with the other hand, twist it in a circle and push the loop from your other hand, through the second loop. As you tighten you will see the figure eight form in the line and thus know it has been done correctly, before tightening all the way.
Martingale – often used in fly fishing or anywhere you may have to join two different types/weights of line, or add leader. Form a figure eight knot in each of the tag ends, then snip the tag end of each. The upper knot tag end should be snipped right to the knot as you will catch line on the knot while casting, something that is a pain because you have to bring in the entire mess – which if your fly/lure is rotating becomes a total mess and pain – to lift the caught line off. This is because the knot faces ‘up’ line. The knot on the down side of the knot seldom catches line because it is not facing the line.
Take the upper loop, push it through the loop on the lower section of line, pass the tag end of the lower piece of line through the upper loop and pull that line all the way through, the loop on loop connection is a Martingale. It is important to always push the upper loop through the lower loop first, as if you don’t you will find that sometimes after pulling the entire lower line through and tossing it into the water that you have just untied the second piece of line and just lost it.
Clinch Knot – the most common fly fishing knot for tying a fly on the tag end of the leader. The alternative is a loop knot. Slip the tag end through the eye on the fly, take the tag end around and, if there is room, slip the tag end of the line through the fly’s eye once again, which makes it twice as strong. (Sometimes, when you have used too much head cement on the eye, it gets too clogged to push the leader through again).
Wind the tag end around the standing line 7 or 8 times, alternatively, twist the fly around in 7 to 8 circles, then the tag end goes through the small opening of line near the eye. Tighten and you have a Clinch Knot. Even better, before tightening, bring the tag end back through the loop formed by putting the tag end through the small opening, and you have an Improved Clinch. Even better, as you tighten, stop and pull the tag end. This results in an improved clinch, that has a loop between it and the fly eye. The purpose is to give the fly more action as it can freely move because the knot is not tightened onto the eye but the line itself.
Guides Wrap/Snelled Hook Knot – used when you are making up rigs of two hooks with six feet of leader, either singles or treble first and trailing single, commonly used for squirts, hootchies and teaser-head bait rigs in salt water trolling. Pass the tag end through the hook eye, form a loop, and hold the loop and tag end along the shank with one hand, tag end extended an inch from the bend.
Take the loop in your second hand and wrap it around the held shank, loop and tag end at least six times, then hold the loop in your first hand. Pull the tag end with your second hand and a knot lays down neatly against the shank. The tag end is left – at least six inches – to tie the trailing hook the same way. The knot is also known as a sliding knot as you can slide the knot up and down the hook shank, thus shortening the distance between the two hooks, or the distance the trailing single will extend from the lure/bait’s trailing end.
Nail Knot/Nailless Nail Knot – commonly used to tie a loop in the end of a fly line. Form a loop in the flyline tag end, and form a loop of leader along the flyline loop, as you did in the Snelled Knot above. Again the tag end of the leader extends an inch beyond the flyline loop. Wrap the loop around the flyline loop six to eight times, secure the loop and pull the tag end. This lays down a nice compact knot around the flyline loop. Snip the knot on the upside as close to the knot as possible, to avoid line catching on it during casting. Finish with head cement, nail polish, or other adhesive, that covers the upper tag end.
There are many other knots you can use, for example, the Allbrite, but the above cover most situations you will run into.