resp, err := http.Get("https://api.vk.com/method/users.get?user_ids=" + id + "&fields=about,activities,books .....
resp, err := http.Post("https://api.vk.com/method/users.get","POST",_)
import (
...
"net/http"
"net/url"
"strings"
...
)
func main() {
...
data := url.Values{}
data.Add("user_ids", id)
data.Add("fields", "about")
data.Add("fields", "activities")
data.Add("fields", "books")
resp, err := http.Post("https://api.vk.com/method/users.get", "POST", strings.NewReader(data.Encode()))
...
}