Friendship is the essence of Vedic marriage. There are many types of Vivaha or wedding in the Hindu Tradition. The Wedding of Shakuntala and Dushyantha is a gandharva - vivaha, a marriage by mutual consent, without any wedding ceremony.
The most common wedding is vaidika-vivaha, also known as the brahma-vivaha. In this wedding a number of guests are invited. Everyone present is a witness to the wedding including brahmanas(priest), agni(fire). Your heart and mind are witness the wedding. Finally saksi or atma is also a witness to the wedding. The marriage is coming together of two pilgrims journeying towards the same destination. Swami Dayananda Saraswati
Sites explaining rituals
www.vivaaha.org/
Topics on Marriage dicussed include:
Significance of Marriage Types of Marriages in Ancient India Hindu Marriage Ceremony Vedics Mantras in Marriage Vedic Astrology and Marriage
www.ramanuja.org/
Under "worship, rituals and sacraments" there is a topic on "The Vedic Wedding". With an Explanation of the traditional hindu marriage.
www.mypurohith.com/
Under matrimonials tab the site discusses Hindu Marriage Ceremony,Rituals during Marriage and Types of Vivaah.
en.wikipedia.org/wiki/Hindu_wedding
Under Hindu teaching and customs of marriage the following topics are discussed; Contents. Reception of the bridegroom The giving away of the bride The Nuptial Homa Acceptance of Hand Solemn vows Ascending the slab / Stepping on the stone The fried-rice offerings Circumambulation around the sacred fire Seven Steps Sprinkling of water Meditating on the sun Touching the Heart Meditating upon the Pole Star and the Arundhati Start Partaking of food Benediction Reception of the bridegroom
Books on Hindu Wedddings
"Vivah" by Meenal Atul Pandya
"Explore Hiduism" by Bansi Pandit
"Samskaras" by Krishna Bhatta