So once you have fallen in love with God, it really helps to have a spiritual director of some sort.
When I was in the midst of discerning my vocation, I was blessed enough to have a regular Confessor and a spiritual director. Often, if you have a priest as your spiritual director he can also serve as your regular Confessor.
Once you're deep in the midst of the steps taken to commit to your vocation, you will have a built in system of spiritual guides to avail yourself of. Those going through marriage prep usually work closely with their pastor and/or lay ministers trained to talk through the spiritual/emotional aspects of discerning a marriage. Those in seminary normally have spiritual directors and Confessors, as do those in religious communities.
I'm not talking about that stage of your discernment - the stage where you basically know (or think you know) what direction you are being called in and it's just a matter of making sure. (Those who are engaged or novices or seminarians do sometimes discern that that is not their vocation and that is perfectly fine! That is what that stage of preparation is intended to do - weed out those who do not actually have those vocations and further prepare those who do.)
No, I'm talking about the stage before that - the stage when you are not yet (or just beginning) to date someone, or just starting to look into different religious communities or diocesan programs. In that very early stage, it helps to have someone by your side who can help you discern if you are on the right track.
Now let me be clear. A spiritual director and/or Confessor is not someone with all the answers. They are meant to be companions, who pray with you and help to point out where the Holy Spirit is at work in your own life. A good spiritual director will not tell you, "I think X is your vocation." A good spiritual director will tell you, "Let's pray about your vocation together," or "It seems the Holy Spirit may have been working through X experience. Let's pray about it." The Holy Spirit must be at work in these relationships.
As for the specifics? Kendra has an excellent primer on spiritual direction. If in doubt about who to ask, your pastor may also be able to point you in the right direction. If you are fortunate to still be in school (high school/college/grad school) then your Campus Ministry or Catholic student center would be the place to go.
In all honesty, I haven't had a spiritual director for a while, but would probably benefit from one! Even once you have discerned your vocation, even after you have said yes, it still helps to continually discern what God is asking of you!
Please continue to pray for vocations with us!
O God, Father of all Mercies,
Provider of a bountiful Harvest,
Provider of a bountiful Harvest,
send Your Graces upon those
You have called to gather the fruits of Your labor;
preserve and strengthen them in their lifelong service of you.
Open the hearts of Your children
that they may discern Your Holy Will;
inspire in them a love and desire to surrender themselves
to serving others in the name of Your son, Jesus Christ.
Teach all Your faithful to follow their respective paths in life
guided by Your Divine Word and Truth.
Through the intercession of the Most Blessed Virgin Mary,
all the Angels, and Saints, humbly hear our prayers
and grant Your Church's needs, through Christ, our Lord. Amen. (source)