Here's the bulk of a post I made several weeks ago concerning the indwelling of the Holy Spirit:
There are several places in scripture where the Holy Spirit made His presence felt in the lives of many, not just the original Apostles. However, for clarity's sake, let's start in the book of John, chapter 20, when a resurrected Jesus appears to His disciples:
John 20: 19-23:
19 Then on that same first day of the week, when it was evening, though the disciples were behind closed doors for fear of the Jews, Jesus came and stood among them and said, Peace to you!
20 So saying, He showed them His hands and His side. And when the disciples saw the Lord, they were filled with joy (delight, exultation, ecstasy, rapture).
21 Then Jesus said to them again, Peace to you! [Just] as the Father has sent Me forth, so I am sending you.
22 And having said this, He breathed on them and said to them, Receive the Holy Spirit!
23 [Now having received the Holy Spirit, and being led and directed by Him] if you forgive the sins of anyone, they are forgiven; if you retain the sins of anyone, they are retained.
Personally, I would equate the occurrence in John 20 as the initial salvation experience of Jesus' disciples seeing as the disciples now know without a doubt that the ressurected Jesus is indeed the Christ.
Scripture then speaks of a secondary occurrence; an enduement of power from on high for the fulfillment of the Great Commission. Look no further than Acts, chapters one and two for a scriptural example of this occurrence when the original 11 disciples and 109 others receive of of the Holy Spirit:
Acts 1: 3-8:
3 To them also He showed Himself alive after His passion (His suffering in the garden and on the cross) by [a series of] many convincing demonstrations [unquestionable evidences and infallible proofs], appearing to them during forty days and talking [to them] about the things of the kingdom of God.
4 And while being in their company and eating with them, He commanded them not to leave Jerusalem but to wait for what the Father had promised, Of which [He said] you have heard Me speak.
5 For John baptized with water, but not many days from now you shall be baptized with (placed in, introduced into) the Holy Spirit.
6 So when they were assembled, they asked Him, Lord, is this the time when You will reestablish the kingdom and restore it to Israel?
7 He said to them, It is not for you to become acquainted with and know what time brings [the things and events of time and their definite periods] or fixed years and seasons (their critical niche in time), which the Father has appointed (fixed and reserved) by His own choice and authority and personal power.
8 But you shall receive power (ability, efficiency, and might) when the Holy Spirit has come upon you, and you shall be My witnesses in Jerusalem and all Judea and Samaria and to the ends (the very bounds) of the earth.
Acts 2: 1-4:
1 And when the day of Pentecost had fully come, they were all assembled together in one place,
2 When suddenly there came a sound from heaven like the rushing of a violent tempest blast, and it filled the whole house in which they were sitting.
3 And there appeared to them tongues resembling fire, which were separated and distributed and which settled on each one of them.
4 And they were all filled (diffused throughout their souls) with the Holy Spirit and began to speak in other (different, foreign) languages (tongues), as the Spirit kept giving them clear and loud expression [in each tongue in appropriate words].
For further scriptural proof of yet another corporate physical manifestation of the Holy Spirit, look no further than Acts chapter 4 after Peter & John's arrest:
Acts 4: 23-33:
23 After they were permitted to go, [the apostles] returned to their own [company] and told all that the chief priests and elders had said to them.
24 And when they heard it, lifted their voices together with one united mind to God and said, O Sovereign Lord, You are He Who made the heaven and the earth and the sea and everything that is in them,
25 Who by the mouth of our forefather David, Your servant and child, said through the Holy Spirit, Why did the heathen (Gentiles) become wanton and insolent and rage, and the people imagine and study and plan vain (fruitless) things [that will not succeed]?
26 The kings of the earth took their stand in array [for attack] and the rulers were assembled and combined together against the Lord and against His Anointed (Christ, the Messiah).
27 For in this city there actually met and plotted together against Your holy Child and Servant Jesus, Whom You consecrated by anointing, both Herod and Pontius Pilate with the Gentiles and peoples of Israel,
28 To carry out all that Your hand and Your will and purpose had predestined (predetermined) should occur.
29 And now, Lord, observe their threats and grant to Your bond servants [full freedom] to declare Your message fearlessly,
30 While You stretch out Your hand to cure and to perform signs and wonders through the authority and by the power of the name of Your holy Child and Servant Jesus.
31 And when they had prayed, the place in which they were assembled was shaken; and they were all filled with the Holy Spirit, and they continued to speak the Word of God with freedom and boldness and courage.
32 Now the company of believers was of one heart and soul, and not one of them claimed that anything which he possessed was [exclusively] his own, but everything they had was in common and for the use of all.
33 And with great strength and ability and power the apostles delivered their testimony to the resurrection of the Lord Jesus, and great grace (loving-kindness and favor and goodwill) rested richly upon them all.
The original Apostles were not the only ones to receive the Holy Spirit in such manner. In Acts chapter 10, Cornelius (a Roman centurion) and his entire household of gentiles receive the Holy Spirit in like manner after God had revealed to Peter that salvation is for both the Jew & Gentile:
Acts 10: 44-46:
44 While Peter was still speaking these words, the Holy Spirit fell on all who were listening to the message.
45 And the believers from among the circumcised [the Jews] who came with Peter were surprised and amazed, because the free gift of the Holy Spirit had been bestowed and poured out largely even on the Gentiles.
46 For they heard them talking in [unknown] tongues (languages) and extolling and magnifying God.
In Acts 19 we find another occurrence where yet another group of people receive of the Holy Spirit in similar manner:
Acts 19: 1-7:
1 While Apollos was in Corinth, Paul went through the upper inland districts and came down to Ephesus. There he found some disciples.
2 And he asked them, Did you receive the Holy Spirit when you believed [on Jesus as the Christ]? And they said, No, we have not even heard that there is a Holy Spirit.
3 And he asked, Into what [baptism] then were you baptized? They said, Into John’s baptism.
4 And Paul said, John baptized with the baptism of repentance, continually telling the people that they should believe in the One Who was to come after him, that is, in Jesus [having a conviction full of joyful trust that He is Christ, the Messiah, and being obedient to Him].
5 On hearing this they were baptized [again, this time] in the name of the Lord Jesus.
6 And as Paul laid his hands upon them, the Holy Spirit came on them; and they spoke in [foreign, unknown] tongues (languages) and prophesied.
