Two things:
- You want a pop filter:

- You can use techniques to avoid the negative effects of sibilants (s and soft c) and plosives (t and p).
Bad-sounding sibilants and plosives have one thing in common: they are unvoiced. That means that your voice box is not vibrating when you say them - they are created just with air moving past the lips and tongue. One way to avoid bad sibilant and plosive sounds is to substitute their voiced versions:
- Instead of S sounds, sing Z or SH/ZH sounds
- Instead of T sounds, sing D sounds
- Instead of P sounds, sing B sounds
So for instance, The Star Spangled Banner might start off more like, "Oh, shay can you zhee..." Now you're probably thinking "That's going to ruin my lyrics!" (or maybe "Thadz going do ruin my lyricsh!", and you have a good point. The trick is to practice so that you are kind of half-voicing those consonants. Along with the fact that you are singing and the subtle differences between ears and microphones, sounds halfway between s and z or t and d actually sound correct in context.
So between a pop filter, a de-esser (which is a necessary evil signal processor for dealing with sibilants), and most of all, practiced technique (it's alway practice, isn't it?), you can get great vocal recordings.
One source: The Craft Of Singing (book)
Also: Singing Sibilance and How to Solve It (YouTube video)