The player to the left of the declarer makes the opening lead. Leads are hard because it's the only time you have to play a card before seeing dummy. However, you can use clues from the auction to help your decision.
Which suit to lead
There are many rules about opening leads but using clues from the auction to help build up a picture of the missing cards will give you better ideas about what to lead and how to defend rather than blindly following convention.
East is declarer in 1NT and you're on lead. Clubs are your best four card suit but this fairly common auction suggests that might not be your best choice
You have to ask yourself what does East have for that 1NT bid? East doesn’t have a 4 card heart suit or a 4 card spade suit because she would have bid 1♥ or 1♠ rather than 1NT. East probably doesn’t have a whole bunch of diamonds, either, otherwise she might have supported West’s 1♦ opening. So if East doesn’t have spades, hearts or diamonds..
..must have clubs. OK, let’s lead a heart. Here is the full hand:
Leading your long suit
If partner has bid, that will often solve your dilemma. If your suit has been bid by an opponent, it could be unwise to lead it. If partner hasn't bid, it's normally best to lead your longest suit against a notrump contract.
Short suit leads.
Against a suit contract, as well as the possibilty of establish tricks in your long suit, you also have the option of leading a short suit to try and score a ruff.
An opening lead of a trump can sometimes be an effective way of preventing declarer taking ruffs in dummy. One clue to when it might be the right thing to do is when you know dummy's side suit isn't breaking well.
When the opposition have rushed off to game in a couple of bids then there's no time to waste. You need to attack even if it means leading away from your honour cards. You just have to hope partner has help in your best suit. However, when the opponents have crawled into game you're often better off making a safe lead.
Peanut butter sandwich leads
When you don't know what to lead you should eat a peanut butter sandwich. That way if your lead doesn't work out well at least you get to eat a peanut butter sandwich.
Top of a sequence
Leading the ♠K might lose to the ♠A but then your SQJ will be set up and you might even make a trick with the 5 if your opponents run out of spades. The lead of an honour promises a sequence so by leading the ♠K partner will know you have the ♠Q. Partner can use a signal to encourage or discourage you from continuing that suit.
You don't have a sequence this time but if you lead a low spade you still might be able to establish some tricks in that suit. The lead of a low cards promises an honour so your partner will know that's the suit you would like to establish.
Leading the fourth highest card, the ♠5 in this case, can be helpful for partner to figure out the location of the missing honours using the rule of 11.
Leading away from an ace
Against a suit contract, it's not a good idea to lead a low card from a suit in which you hold the ace otherwise by the time you do play your ace declarer might be void in that suit! Normally it's best to lead another suit altogether in this case.
Top of a doubleton, top of a weak suit.
This time no lead looks particularly attractive but if there is only one unbid suit that can be a good option. Lead the ♠8, top of a doubleton, and partner will know you don't have an honour in the suit.
Is it possible to have a column showing what was the other players first lead was
The section re what 'what suit to lead' needs to change to E/W. Showing N/S
But really enjoying the sections. Just needs to come to fruition when when I play! I am sure that will happen😏