You learned what these are at seminary, but we'll quickly review. If you need help with what the things actually look like, Ken Collins has descriptions and pictures.
Now, basically, as a Newly Ordained Person in The Episcopal Church, you've got two big categories to think about. The first is the category of Choir Dress. The second is the category of "liturgical" or "sacramental" vestments.
You wear choir dress when you are sitting in choir. Seriously. In practice, this means you are doing something liturgical that isn't technically leadership in a sacramental liturgy. Evensong? Not sacramental, so you wear choir dress. Officiating at Holy Matrimony? Sacramental, so you don't wear choir dress. Attending, but not participating in a festal Eucharist? You aren't acting as a leader in a sacramental liturgy, so, yup, choir dress. Alright, now, Christian Burial without a Eucharist? Here's the tricky question. The tradition of the church does not consider Christian burial to be a sacrament (sacraments are for the living), so you'd wear choir dress.
In our tradition, this means at least a cassock and a surplice. If you want to get more formal, add a tippett. If you want to get really formal, add a hood. The Anglican look is the round-yoked surplice that is fully gathered. There is a Roman surplice that is square-yoked and pleated. It looks good, don't get me wrong, but it doesn't look good with tippett and hood.
Your tippett will be black. You can certainly have the seals of your seminary and The Episcopal Church sewn to it. Check with your bishop first, or your rector if you start out as a curate. Both Almy and Church Publishing sell tippet seals. Church Publishing's are much, much nicer.
You wear these when you're leading in a sacramental liturgy. Again, things break down basically by how high up the candle you are. You're likely to see:
- alb/stole/chasuble (at the Eucharist)
The first option is common for Low-church/Evangelical settings. Here, you could easily go with either the English (gathered, round-yoked) surplice, or with the Roman (pleated, square-yoked) surplice. Pop a stole on over that, and away you go.
The second option is I think probably the main-stream in Episcopal Church parishes these days. The alb is the basic white garment of the baptized. The stole is a symbol that goes with the order of ministry. This is why deacons have one kind and priests another. The cope has nothing to do with holy orders at all. It just looks jolly nice. A bishop might wear a cope in a liturgy in which he or she wasn't presiding. A lay person might wear a cope to officiate at a solemn Evensong. The chasuble is a functional symbol; it means that you are the presider in the sacrament of the Eucharist.