Psalm 121 - If you remember, Psalm 120 - 134 are considered "Songs of Ascent" meaning they were worship songs sung by pilgrims on their way to Jerusalem for the yearly feasts. Jerusalem is "up" and the Temple is where God's Presence is and so, if you were looking for your help, your Help was up in the hills in Jerusalem. Therefore, the Psalmist is not saying, "You need to look for the Lord and not the hills for your help." He is saying, "Look for the Lord who resides IN the hills, for it is IN the hills where you will find the Lord who is your Help!"
Psalm 123 - A servant or a maid wasn't paid a salary. They looked to their master or mistress to provide for them. We, as God's servants, look to Him for our daily needs.
Psalm 124 - When you think you're all alone, you're not! God is always at hand and He won't deliver you over to the enemy.
Psalm 125 - Continuing from the last Psalm, you don't just have the Lord with you, He surrounds you! Remember when Elisha was surrounded by the enemy? Actually the enemy was surrounded by God and His angels!
Psalm 128 - God's blessing comes on those who have learned the value of truly fearing Him. We never need to be afraid of the Lord, unless we're living in sin. We should, however, always possess an awesome respect and reverence for Him. God blesses those who have that.
Psalm 129 - There will be times when you may feel persecuted, or at least troubled by those who hate God. In God's time, always the best time, He will bring your enemies to shame and bring you to victory.
Psalm 130 - Thank God that He doesn't hold our sins against us when He forgives! He wants us to find hope in His Word and believe what He says about not only forgiving us, but also restoring us too.